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THE M4NUE4CTURE OF YARXISHE^ 
" AND KINDRED KDUSTPJES ' 



' I 



LIYACHE AND .McINTOSH 



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THE MANUFACTURE OF 

VARNISHES 



AND 



KINDRED INDUSTRIES 

BASED ON AND INCLUDING THE " DRYING OILS AND VARNISHES ' 

OP 

ACH. LIVACHE 



JOHN GEDDES McINTOSH 

• I 

L.ATE LECTURER ON VARNISH MANUFACTURE AT THE POLYTECHNIC, REGENT STREET, AND 
THE BOROUGH POLYTECHNIC 



JSECOND, GREATLY ENLARGED, ENGLISH EDITION, IN THREE VOLUMES 

VOLUME I. 

OIL CRUSHING, EEFINING AND BOILINa 

THE MANUFACTURE OF LINOLEUM 

PRINTING AND LITHOGRAPHIC INKS 

AND 

INDIA-RUBBER SUBSTITUTES 



SCOTT, GEEENWOOD & SON 

"THE OIL AND COLOUR TRADES JOURNAL" OFFICES 
8 BROADWAY, LUDGATE HILL, E.G. 



CANADA: THE COPP CLARK CO., LTD., TORONTO 
UNITED STATES: D. VAN NOSTRAND CO., NEW YORK 

1904 ) , 

[All rights^ inehtdin(f the sole right of tratisloMmi into EngllsJi of M. Llro.che^s treatise, 
remain with Scatty Greenwood <t Soti] 

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THE MANUFACTURE OF VARNISHES 

AND 

KINDRED INDUSTRIES 

VOLUME I. 

OIL CRUSHING,' REFmiNG AND BOILING, 

THE MANUFACTURE OF LINOLEUM, 

PRINTING AND LITHOGRAPHIC INKS 

AND 

INDIA-RUBBER SUBSTITUTES 



258395 

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CONTENTS 



PAOB 

Pbefacs vii 

CHAPTER I. 
OUi Gbubhino and Refining 1 

CHAPTER II. 
Oil Boujno— Theobbtical and Practical 22 

CHAPTER in. 
Linoleum Manufactubb 57 

CHAPTER IV. 
Pbintinq Ink Manufactube . 62 

CHAPTER V. 
RuBBEB Substitutes 72 

CHAPTER VI. 
The Manufactube of Dbiebs 84 

CHAPTER VII. 
The Detection of Adultebation in Linseed and otheb Dbyino Oils 
bt Chemical, Physical and Oboanoleftic Methods ... 94 

Index . i 147 



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PREFACE TO THE SECOND EDITION 

Owing to the extensive enlargements made in this second 
edition it has been advisable to subdivide the book into 
three volumes. 

The publication of Volumes II. and III. will speedily 
follow. Each volume, like the present one, will be complete 
in itself, and no pains have been spared to render them 
useful, reliable and up-to-date. 

No second edition of the work of M. Livache has 
yet appeared. I am therefore solely responsible for the 
numerous additions that have been made to both the 
first and second editions. May the reception of the latter 
be as cordial as the first. 

J. G. M. 
London, June., 1904. 



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CHAPTEE I. 

OIL CRUSHING AND REFINING. 
Drying Oils. 

Definition. — The drying oils are those oils of vegetable origin which, 
being Hquid at the ordinary temperature, possess the property of gradu- 
ally and progressively absorbing oxygen from the air at the ordinary 
temperature, and in so doing, instead of yielding a rancid, more or 
less viscous, greasy mass, change gradually and eventually by insen- 
sible gradations from the original condition of a fluid oil into solid 
elastic substances insoluble in the usual oil solvents. 

The greater the quantity of oxygen which such an oil is capable 
of absorbing in this way, the greater are its drying propensities and 
properties, and vice versd. 

The sequel of changes which such an oil undergoes is termed the 
drying of the oil. As a matter of fact, the oil does not dry in the true 
acceptation of the term. When a substance in ordinary language is 
said to dry, what is meant is that the substance in question loses any- 
adherent, adventitious or interstitial water or hygroscopic moisture,, 
and, in a case of drpng of that nature, we can appreciate the change^ 
as it proceeds, both by the eye and the touch. The vapour is visible-- 
to the eye as it condenses, and the touch is sensible to the drier feel- 
ing as the moisture is expelled to a greater and greater extent. Such 
svhstanceSj therefore, suffer a diminution in weight corresponding to* 
the amount of water eliminated in the process. But a phenomenon of 
quite an opposite nature occurs when a drying oil dries ; instead of 
losing in weight it gradually becomes heavier as the ** drying ** process 
proceeds, until the oil has completely ** dried,** when its weight will 
be found to have increased some 16 to 17 per cent. In other words, 
10 gallons of linseed oil, spread over any given surface, will not only 
increase the weight of the object on whose surface it was painted by 
the weight of the 10 gallons of oil, but, when the oil dries, the object 
will be found to have increased in weight by 110 lb., 93 lb. of which 
are due to the oil and some 17 lb. due to the absorption of oxygen 
gas from the air. Now a gallon of oxygen weighs about 96 grains, 
and as there are 7,000 grains in a pound, and as 17 lb. of oxygen 
were absorbed, we get a total of 119,000 grains of oxygen absorbed 
by the oil, which, divided by 95 grains, gives us nearly 1,253 gallons 

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•*• : >' I y : • .•' •; : .i^^AirtrFAtTURE of varnishes. ^ ^ 

of oxygen gas as being required to dry 10 gallons of oil. But the air 
only contains i of its volume of oxygen, so that 6,265 gallons of 
air are totally deprived of oxygen by the drying of 10 gallons of 
linseed oil. This is a point in connection with the bad effect of 
sleeping in newly painted rooms which has not received from 
the medical faculty the attention it deserves. The headaches 
and other symptoms may, on investigation, prove not to be due 
either to the toxic effects of turpentine or to linseed oil emanations, 
but to the rapid manner in which both diminish the proportion of 
oxygen in the superincumbent atmosphere by the energej^c way in 
which they absorb oxygea But there need be no serious effects pro- 
vided ventilation be attended to. The doing away with fireplaces 
and heating bed- and sitting-rooms by steam is much to be depre- 
cated. An ordinary svhstance in drying loses water and loses in weight. 
A drying oil in drying absorbs oxygen and increases in weight. More- 
over, if we can see the water being expelled from an object by the 
clouds of steam which are formed in the process, and although we 
may increase the rapidity of drying of linseed oil by the application 
of not too great a heat, such as '* drying " the article in a hot- water 
oven, or a current of air, yet in no instance can vapour be seen to 
rise from pure and good linseed oil, unless the heat be raised so as to 
start the destructive distillation of the oil. If the oil contain spirits 
of turpentine, naphtha, etc., it will of course give off a considerable 
vapour at a much lower temperature than linseed oil pure and 
simple. 

When linseed oil in its pristine liquid condition is spread over 
the surface of an object which has been made impervious by the 
process known as priming, that is to say, its pores have been filled 
up in a suitable manner, it forms when dried an impervious coating, 
which still further protects the object from the effects of wear and 
tear and all those extraneous erosive agencies which we know imder 
the term weather, such as the difference in temperature between day 
and night, summer and winter, heat and cold, rain, frost and snow. 

The Fimction of Drying OUs as Vehicles for Pigments. — To increase 
the thickness of the coating, and also to form a harder, more per- 
manent, more anti-corrosive and more anti-erosive layer, the drying 
oil is generally mixed with substances known as pigments. The oil 
in drying cements these pigments to the object to which the mixture 
of oil and pigment is appUed. The mixture of oil and pigment is 
called a paint. The drying oil is said to act as the vehide. We 
thus often hear of pigments and vehicles. But a vehicle would be 
of no use unless it acted as a lasting binding agent as well. Colza 
oil would form as good a vehicle for pigments as linseed oil, if not 
better ; but as colza oil is a non-drying oil, the paint made by using 
it would not be a paint at all, as the vehicle would not dry, and thus 
it would not solidify itself, and hence it could not consolidate the 
particles of pigment and itself into a hard impervious layer, and the 
mixture would be more suitable for axle grease than for paint pur- 



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OIL CEUSHING AND EEFINING. 3 

poses. In the same way size, the vehicle used in distemper painting, 
is a good enough vehicle for indoor work when applied to the walls 
of rooms, but the denuding and erosive action of the weather would 
render it worse than useless when applied out of doors. 

The word vehicle as used by some writers is, therefore, an in- 
complete definition of the functions of a drying oil when applied in 
conjunction or in combination with a pigment to the surface of an 
object. It is the cementing or binding agent, or vehicle, if you will 
— just as slaked lime is the agent which binds the sand in the 
mortar to the wall. Not only so, just as the lime cements the 
particles of sand to themselves and to itself and the agglomerate 
thus formed to the wall, so also does the linseed oil cement the 
particles of pigment to each other and to itself and the agglomerate 
thus formed to the object to which it is applied. But the analogy 
does not rest here; the slaked lime also increases in weight in 
drying. Although it gives off moisture it nevertheless at the same 
time absorbs carbonic acid. For every 18 parts of chemically com- 
bined water which mortar gives off in drying and consolidating it 
absorbs 44 parts of carbonic acid, and consequently increases in 
weight, as we have just said. 

Summary, — The function of a drying oil when used as a vehicle 
for paints is to so '' dry ''as to bind and consolidate the pigment in 
such a way that the combined layer formed by the dried vehicle and 
pigment, that is, by the dried paint, will withstand the heat of the 
sun's rays, the erosive action of the weather, and in conjunction 
with the pigment protect the object to which it is applied hrom the 
corrosive and erosive action of the same, 

The Function of Drying Oils as Varnish Ingredients , i.e., as 
** Vehicles " for Besins. — The chief function of drying oils as in- 
gredients of varnishes is first of all to dissolve the resin so as to bring 
it into the fluid condition; here again colza and other oils would 
act similarly, but the solution of resin in colza oil would never dry, 
and the only use for such a product would be for axle grease, and 
even for that purpose it would not be very fit, and not only so, it would 
be a very costly way of making axle grease. Here again the function 
of the linseed oil is to dry, and in so doing to cement together the 
particles of resin by an elastic binding agent consisting of the product 
into which the linseed oil is resolved on drying. The greater the 
quantity of linseed oil and the fewer the particles of resin which it 
has to cement together, and which are present in a '' dried " coating 
of varnish, the more elastic and durable will be that coating. If a 
linseed oil substitute consisting of hydrocarbides, such as rosin oil, 
be substituted for a drying oil, e.g., linseed oil, whether in a paint or 
varnish, this durability and elasticity is lost, the dried product dis- 
solves in weak solutions of alkali, and even in warm solutions .of 
household soap, as is seen in the case of the front door of the house- 
wife who must always be scrubbing. Her newly painted and 
varnished front door in a few months looks as if it had not been 



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4 MANUFACTURE OF VARNISHES. 

painted or varnished for as many years. Moreover, the melting- 
point of the dried product of linseed oil is very high, as any one may 
satisfy himself by trying to melt linseed oil skins, but the melting- 
point of the "dried ** (sic) product of hydrocarbide oils, e.g,, rosin oil, 
is no better than that of common rosin. Moreover, the dried product 
of such oils or varnishes is soluble in the original varnish, especially 
in the sun, when the former melts, a fact which gives rise to many 
exasperating difficulties when it is desired to apply a second coating 
of the same paint or varnish on the same article. In the cool of the 
evening the coating may be as " dry as a bone,'' in the heat of the 
day it is simply a liquid pitch, and if the coating does eventually so 
dry and harden as to withstand the heat of the sun, it is such a mass 
of cracks and furrows that those on an elephant's hide might well be 
compared to them. These cracks and furrows are produced by the 
difference in temperature between day and night, producing hundreds 
of alternate liquefactions and solidifications of the coating, into the 
composition of which this linseed oil substitute enters so largely. 
Moreover, in the cool of the evening the coating seems to dry, but it 
is merely surface drying, underneath is a layer of liquid pitch like that 
of a lake of asphaltum, and it only requires the heat of the sun to 
melt 'the surface crust to liberate streams of the liquid confined beneath. 

The great function and characteristic property of a drying oil is 
to yield on drying a coating of high melting-point, great elasticity, 
great imperviousness and great durability, and resisting both natural 
and artificial reagents and solvents. 

Linseed oil substitutes have one advantage : they are easily re- 
moved when necessary, and, in their case, one need not go far to 
find a paint remover. There is no necessity to bum it off, as in the 
case of good genuine linseed oil. Were the latter more used there 
would not be such a market for the numerous brands of more or less 
efficacious " paint removers ". 

The drying oils employed by varnish manufacturers are (1) lin- 
seed oil, from Linum usitatissimum (the flax plant) ; (2) poppy-seed 
oil, from the Papaver sonmiferu/m (the opium poppy) ; (3) walLut oil, 
from Juglans regia ; (4) hemp-seed oil, from Cannabis sativa ; castor 
oil, from Bicinus communis, is sometimes used for special purposes. 
Amongst other oils occasionally used, suggested to be used, or said to 
be actually used, are maize oil, sunflower-seed oil, saffiower-seed oil 
and some others. Indeed many other kinds of drying oils occur in i^e 
different organs of various plants, but they are but little used in 
actual practice ; amongst these are cucumber oil, from C%LCwnu& 
sativus ; grape- seed oil, from Vitis vinifera ; bankoul oil, from Aleurite& 
triloba. It is necessary, however, to make special mention of the 
quick-drying oil Paulownie of Jajpan, the fine oil of the Dipterocar- 
pus crispaletus, the Kai-dan-long of the Annamites, and Elaococcay 
Japanese wood oil, the best drying oil known. 

The study of drying oils will, in this small treatise, be confined 
principally to linseed oil, the drying oil par excellence. 



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OIL CRUSHING AND REFINING. 



Linseed Oil. 



The flax plant Lirnrni usitatissimum is a native of Europe and the 
north of Africa, and is said to be indigenous to Britain. The flax 
plant has been oultivated from very anoient times.. We read of its 
having been grown by the Israelites so far back as the time they were 
in Egypt. Flax is cultivated for a double object, firstly^ for the sake 
of its stem, which yields by maceration the tenacious fibres used in the 
manufacture of linen ; and, secondly, for the sake of its seeds, which 
by expression, or extraction by means of solvents, yield linseed oil. 

Flax loves a deep, friable, rather moist soil. It grows well upon 
land newly broken up from pasture. In Ireland it is usually sown 
by the small farmers after potatoes. A fine, nicely pulverised seed- 
bed is essential, and this is rolled after the seed is sown. The usual 
time of sowing is from the middle of March to the end of April. 
Dutch seed is in the highest estimation, affording a greater produce 
than the American seed, and a finer quality than the Eiga. The 
after cultivation consists in taking up the weeds by the hand — the 
only way in which it can be done, and a tedious process if the land 
be at all foul. The crop is raised by pulling up the plant by the 
roots. The produce in seed is from 6 to 8, and sometimes as high 
as 10 or 12, bushels per acre. The best of it is kept for sowing 
again, and the next quality is crushed for oil. Flax, when allowed 
to ripen its seeds, is a very exhaustive crop, even more so than corn, 
and in most parts of Britain is so uncertain that its cultivation has 
hitherto been very limited. But a great deal of flax was at one time 
raised in Ireland Its cultural zone is almost world-wide. 

The linseed imported into England comed chiefly from India and 
Bussia, the former being known as East Indian and the Bussian as 
Baltic seed. The colder the climate in which the seed is grown the 
greater are the drying properties of the oil, but the colour is worse. 
In India white seed is preferred not only because it yields more oil, 
about 2 per cent., but siso because it yields it more freely than red 
seed, and further it furnishes a softer and sweeter cake, which is 
better rehshed by cattle than the cake from white seed. 

White seed comes to market largely adulterated with hemp and 
rape seed. The latter being difficult of separation, greatly depreciates 
the market value of the linseed. La Plata seed is impure and oil bad. 

** Next to cotton-seed oil," says a reliable American authority, ** the 
most important of the United States of America oils is that made 
from linseed. It is only within the past twenty years that the 
cultivation of flax in this country has been of sufficient consequence to 
make the domestic crop of seed come anywhere near supplying the 
demands of the crushers. Flax has been grown in many of the middle 
and Western States for years, but it was not until the broad acres of 
the North- West and the States beyond the Missouri were turned to 
its cultivation that the domestic crop assumed such proportions as 



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6 



MANUFACTURE OF VARNISHES. 



to gradually crowd out the imported. Until about 1880 the American 
crushers had to depend upon the Calcutta or Argentine seed, al- 
though the small mills located here and there through the country 
indicated where local supplies of seed were to be had from domestic 
growers of flax. As the domestic flax is not used for making linen, 
but is grown only for the seed, it is evident that the farmers would 
not have turned their attention to it but for the bounty which was 
offered in a duty of 25 cents per bushel, and even this heavy tax did 
not stimulate them to great activity in this direction until prices on 
wheat and corn began to feel the effects of excessive production. At 
the present time the duty of 25 cents per bushel is prohibitory except 
when seed is being manipulated by speculators. Instead of being 
an importing nation the United States of America have come to be 
exporters under ordinary conditions. The flax-seed crop this year is 
estimated at 19,000,000 bushels, a large portion of which will be 
exported, provided prices are not kept at the high prices now exist- 
ing. The exports of the seed for last season were 2,500,000 bushels. 
There has been a large fluctuation in prices. In my earlier days, as 
a broker, I sold many thousand gallons at 1 dollar 50 cents and 1 
dollar 75 cents per gallon of 8 lb., and of late years it has sold down 
around 27 cents up to 51 cents at the present time. Linseed oil is 
used chiefly in paints, but in Great Britain it finds its way into the 
soap kettles at times when the price is low, although it is not ranked 
equal to some other oils and fats by soapmakers. As yet the price 
has never gone low enough here to make linseed oil a competitor of 
the better-known soap greases, although in 1897 it could have been 
put into the Western soap kettle at a trifle over 3 cents per lb.'* 

Linseed should be kept three to four months, in a dry place, 
before expressing the oil, as the oil furnished afterwards is much 
more abundant than when expressed immediately after harvest. Oil 
from seed which has not been matured in this way is watery, and 
the more so if the seed were not ripe at the time of harvesting. 

The seeds of the flax plant (linseed) consist of small, bright, 
greyish-brown, slippery, elongated bodies, containing a mealy 
oleaginous albumen. 

The chemical composition of the seed is on an average as 
follows : — 

COMPOSITION OF LINSEED. 



Water 

Oil ------- - 

Albuminoids 

Carbohydrates (starch, mucilage, fibre, etc.) 
Ash 



Per cent. 



7-50 
34-00 
24*44 
30-73 

3-33 



10000 



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OIL CBUSHING AND REFINING. 

The composition of the different parts of the seed is as under :- 

/ Gum and soluble salts 14 

T?«;«««»^ 01 ) Soft resin and fixed oil 1 

Episperm - ^liy^^^^^ 2 

Matter insoluble in water and ether - - - 4 

/ Soft resin and fixed oil 6 

Endosperm - 28 j ^[attw soluble in water ' - '. I -" 3 

^ „ insoluble in water and ether- - - 12 

/ Fixed oil 80 

Kernel - - 56 j ^*^ J^. ^^j^'^j^ j^^ ^^^^^j. 3 

^ „ insoluble in water and ether - - - 18 

100 100 



The husk of Unseed is of a purplish-brown colour, and, as will 
be seen from the above analysis, contains much less oil than the 
kernel or nucleus. The kernel is yellowish white in colour, and the 
richest in oil. By expression in the cold linseed yields from 21 to 
22 per cent, of its weight of oil. By the combined action of heat 
and more powerful pressure as much as 28 per cent, may be obtained. 
But if a pure oil is desired expression in the cold is much to be pre- 
ferred, as there is then less tendency to dissolve the mucilage. Ex- 
pression by steam, however, yields a very good oil when the steam 
heat does not exceed 200° F. The usual way of getting rid of the 
large amount of mucilage is by steam heating, after which the seeds 
are bruised and pressed. The marc remaining after expression is 
generally known as oil-cake, and is an article of great value to the 
agriculturist, not only as a direct article of food for cattle, etc., but as 
an indirect way of enriching the soil. A farmer by the consumption 
of a ton of linseed cake on his farm enriches the soil to the same 
extent as if he had spent a very considerable sum on chemical 
manures. 

Linseed oil-cake has the following average composition : — 



Water - 
Albuminoids 
Oil 

Carbohydrates 
Fibre - 
Ash - 




The higher the temperature and the more powerful the pressure used 
to express the oil from the seed the less valuable is the cake. The oil 
varies in genuine cakes from 8*5 to 13 per cent., but is generally from 
10 to 11*5 per cent. The albuminoids vary from 26 to 32 per cent., 
but on an average are about 26 per cent. The ash ranges from 5 to 
9 per cent., but is usually from 5'8 to 7 per cent. Good linseed cake 



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MANUFACTUBE OF VARNISHES. 



has a reddish-brown colour, uniform appearance and pleasant mild 
flavour and odour. Very dark cakes are generally over-heated, and 
very white ones adulterated. Oil-cake is said not to be a good food 
for pigs as it renders their flesh soft and oily. 

The Gbushing of Linseed. 

Bolls. — The first process in crushing linseed is to pass it through 
the rolls (Fig. 1). It is conveyed to the hopper by an elevator or 
chute, and is distributed to the rolls (Fig. 1) by a fluted feed roll 
the same length as the feed rolls at the bottom of the hopper. From 
the feed roll it falls on a guide-plate, which carries it between the 
first and second rolls. After passing between these rolls and being 
partially crushed it falls on a guide-plate on the other side, which 

carries it between the second 
and third rolls, where it is 
crushed more fully. It then 
falls on another guide-plate, 
which carries it between the 
third B,nd fourth rolls, where 
it is ground more fully still. 
In the larger rolls it falls on 
a fourth guide-plate, where 
it is conveyed between the 
fourth and fifth rolls and 
receives the final grinding. 
The seed is thus crushed 
four times in its passage 
through the rolls, which, 
being brought into contact 
by a combination of a screw 
and spring, give a smooth 
and easily regulated pres- 
sure. When the seed falls 




Fig. 1. — Rolls for Crushing Linseed. 



from the bottom roll the grinding is found to be much more complete 
and perfect than in seed that has passed through rolls and under 
stones of the old description. 

Steam-Heating Kettle and Moulding Machine, — After passing 
through the rolls the seed falls into a screw conveyer, which places 
it in an elevator that raises it to the steam- jacketed kettle (Fig. 2, A), 
where the seed is heated and damped by a jet of steam and agitated 
by a revolving stirrer. These kettles are made of cast-iron, and are 
constructed in the strongest and best manner. There is only one 
steam joint in them, and that is faced in a lathe or planed quite true. 
There is, therefore, little hability to leakage — always a dreadful 
nuisance. When lagged, the kettle body is fitted with a wooden 
frame, covered with felt, and the felt is enclosed in iron sheeting. 
Up to this point the operations have been automatic. With the 



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OIL CRUSHING AND REFINING. 



9 



Icettle is worked the moulding maohiDe (Fig. 2, B). A man measures 
out sufficient seed for a cake, forms it of the proper shape, cases it 
in a strip of bagging, and passes it to the presses. 

Hydraulic Presses. — Each press holds 16 cakes, and is furnished 
with steel cylinders 16 inches 
in diameter, which carry a 
working pressure of IJ tons 
on each square inch of the 
ram. All the columns, cylin- 
ders, rams and heads are 
planed and turned accurately 
to gauges, so as to ensure 
that every part will take its 
due proportion of strain and 
no more ; the pockets that 
take the colunms are not cast, 
as is usual, with fitting strips 
top and bottom, but are all 
solid throughout, and are all 
machined out of the solid to 
gauges. This method of 
treating the pockets has the 
effect of almost entirely pre- 
venting the columns from 
breaking. In certain types of presses the pockets for the columns 
are bored and the columns are fitted with steel nuts. The plates 
between which the seed is pressed are all well fitted and have a 
corrugated surface. If a brand be required on the cake as, say. 




Pig. 2.— a, Steam Kettle ; 
B, Moulding Machine. 




Fig. 8. 

letters about 3 inches long are clearly cut into one side of the plate 
and all the remainder is corrugated. These plates are all made of 
wrought and cast malleable iron, and the columns are made of best 
scrap iron or mild steel. The cylinder is crucible cast steel. 

Pumps, — The pumps are made of the highest class of crucible 
cast steel and are all bored out of the solid. Two of the pump rams 
are 2^ inches in diameter and have a stroke of 7 inches. These rams 
give only a limited pressure, and the arrangements are such as to 



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10 



MANUFACTUBE OF VARNISHES. 



give the limited pressure on each press in about fourteen seconds. 

The pumps then stop automatically. The work is then taken up by 

two other pumps having rams 1 inch in diameter and a stroke of 7 

inches, and is con;tinued by them until a gross pressure of 2 tons per 

square inch is attained. This is the maximum and is arrived at in 

less than a minute. The oil as it comes from the presses falls into 

the tank underneath, which serves as a foundation for the presses^ 

and is pumped from there into the store cisterns. 

Cake Paring and Moulding Machine, — The cakes require paring. 

The parer strips his cake and lays a number of these on a stool or 

table. He takes up one and lays it on the machine (Fig. 5), having 

one side parallel to the trough and overlapping it about an inch, one 

end being placed against a fence, either to the right or left, depending 

on what stroke the machine is 

taking. The knife block passes 

along and cuts one side clean 

and straight. The cake is now 

turned over and the other edge 

treated in a similar manner. 

He now turns the cake half 

round, places one side against 

a fence, and cuts ofiP the oily 

part at one end, then reverses 

the cake and does the same with 

the other end. The cake is now 

ready for the market, and has 

been pared by two double strokes 

of the knives, the speed of which 

is about thirty per minute. 

Fences or gauges may be added 

to give all the cakes one exact 

_ ^ _. length and breadth, but these 

Fig. 4. — Pumps. f • . i 

make more panngs, as the 

fences have to be set to suit the worst cakes. These machines can 

be driven by a shaft either parallel with or at right angles to the 

knife bar, and are suitable for paring either parallel or taper cakes. 

Edge Bunners for Grinding Cake Parings, — The parings are taken 

to the edge runners (Fig. 6) to be ground. These are made of the best 

Derbyshire grit stone, and are furnished with a set of cast-iron centres. 

One centre has a long boss on it, which passes right through the 

stone and the centre on the opposite side, and has a long brass fixed 

on each end of it. These centres are securely fixed to the stones 

with bolts that pass through them, and they are also run into the 

stones with lead. On the outside centre there is a cap fixed with 

screws, quite oil- tight, and large enough to hold several pints of oil. 

The spindle on which the stone revolves passes through the centre 

of the upright shaft, and the stone centre has a cap fixed on each 

end of it with cotters. These caps are enclosed in the oil-cups 




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OIL CRUSHING AND REFINING. 11 

described above, and revolve among the oil contained in them, thus 
causing such a perfect lubrication of the spindle as to make it quite 
unnecessary to withdraw it oftener than once in several months. 
The casting that carries the vertical shaft passes through the bed- 
stone and goes beneath it, projecting beyond its circumference at six 
points, where it is attached to the circular pan above by six brackets. 
The top of this casting is fitted with a " step," constructed in 
several parts, which can be removed or replaced in a few minutes 




Fig. 6. — Cake Paring Machine. 

without disturbing the driving wheels. The vertical shaft is made 
of cast-iron, about 7j inches in diameter, having an oblong chamber 
or naval formed in the centre, into which is fitted a strong cast bush 
having a brass bush at each end through which the stone spindle 
passes. The bush is free to rise and fall in the naval as material is 
added to or taken from the stones. All the sweepers and sweeper 
frames are made of wrought iron. The circular pan is made of cast- 
iron, dished slightly, and having a rim round its circumference 7 
inches deep. All the bearings are brass, made very heavy and 



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12 



MANUFACTUBE OF VABNISHES. 



unusually long. The ground parings are carried from the edge runners 
by a conveyer, from which they fall into the seed kettle. The process 
of refining the crude linseed oil is as follows. The crude oil is taken 
from the store tanks by a force pump into a lead-lined cistern, where 
it is mixed with the necessary chemicals from another cistern. After 
these have done their work and the process, as described hereafter, 

A 




Fig. 6. — Pumps, Presses, Paring Ma,cliine, Edge Runners and Gearing. 



completed, the oil is run into a third tank, where it is agitated by air 
from an air-pump to complete the bleaching and refining process. 

Fig. 7 shows a complete set of the plant above described with the 
exception of the oil-refinery, constituting what is known as the Anglo- 
American Oil Mill, No. 4. It forms the standard size or unit of this 
machinery ; larger mills are made up of multiples of this mill, and 
contain from eight presses upwards. The Anglo-American machinery. 




Fig. 7.— Unit Oil Mill. 



as manufactured by Messrs. Rose, Downs & Thompson, is worked in 
sets of four presses as shown, and a mill can contain any number of 
sets. One set occupies a space 36 feet by 28 feet by 16 feet high, 
and takes 45 horse-power to work it. Additional sets will take about 
35 horse-power each. B4sum4, — The complete process is therefore as 
follows. The seed passes through rolls, 0, from these an elevator, D, 
places it in the kettle, F, from this it passes to the moulding machine, G, 



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OIL CRUSHING AND REFINING. 13 

where it is measured, formed and compressed, and then passed to the 
presses, H. The cakes, after being pressed, are cut to size in the 
paring machines and the parings reduced to meal by the small edge- 
stones, J. The parings are then returned by an elevator to the kettle, 
F, to be re-worked. The presses stand in a tank, into which the 
expressed oil falls and from which it is forced to the store tanks or 
filters by a pump. Fig. 8 shows an illustration of filter press. 

Extraction of Linseed Oil from the Seed by Solvents, — As linseed 
does not lend itself kindly to extraction by solvents, the process need 
not be discussed here ; those interested will find full particulars in 
Andes' Vegetable Oils (Scott, Greenwood & Co.). Moreover, even if 
it were more practicable to extract the oil from linseed in this way 
than it is, it is difl&cult to sell a meal devoid of oil. - — -2 

The Chemical and Botanical Control of Oil Crushing. — Each de- 




PiG. 8.— Filter Press for Oil. 

livery of linseed should be carefully sampled, and the percentage of oil 
determined by means of apparatus shown in Figs. 9 and 10. Frequent 
determinations of the cake from the different presses should be made 
daily, so as to avoid making an unsaleable cake, on the one hand, owing 
to its low percentage of oil, or, on the other hand, leaving too much 
oil in the cake above the guarantee at which the oil miller sells his 
cake. Example : If an oil miller purchases 1,000 tons of linseed con- 
taining 35 per cent, of oil and he guarantees his cake to contain, say, 
13*3 per cent of oil, when it comes to stocktaking he should be able 
to account for 250 tons of oil and 750 tons of cake of above analysis. 
Moreover, the oil miller should, if practicable, contract for his 
seedto contain a minimum percentage of foreign seed, and if he is 
not able to make a microscopic determination himself he should send 
a sample to the botanist of one of the national Agricultural Societies, 



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14 



MANUFACTURE OF VARNISHES. 



say, the Royal Agricultural Society of England or the Highland and 
Agricultural Society of Scotland, so as to get the percentage of seed 
other than linseed. Should the gravity of the oil prove abnormal, 
then this botanical examination may throw light upon the matter. The 
botanist might also be asked to report on the presence or absence of 
v^eeds or their seeds, or vegetable organisms of any nature injurious to 
cattle, as there have been cases decided in court holding the crusher 
liable for the value of cattle dying through eating noxious cake. 



f,^ 



IB 




Fig, 9.— Oil Bxtractor.i 



Pig. 10.— Battery of Oil Extractors 
being Heated on Water-bath. 



Methods of Storing. — Galvanised iron reservoirs are to be pre- 
ferred for storing oil. Their base should be very wide in proportion 
to their height ; they are generally covered by a badly fitting lid, so 
that the air may be constantly renewed on the surface of the oil, but 
it is preferable to use a tight-fitting lid so as to exclude dust. In 
this case a current of air is set up by two tubes placed on opposite 
sides of the reservoir, thus starting oxidation, and thereby increasing 
the drying properties of the oil. It is also of importance to maintain 
the oil at a constant temperature, about 15° to 20"" G. It is advisable 



^ See note, p. 21. 



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OIL CRUSHING AND REFINING. 15 

to draw off the "foots" two or three times a year. It is an un- 
deniable fact that oil kept for a certain time gives a better coating on 
drying to that yielded by an oil fresh from the press. Speaking 
generally, linseed oil should not be used imtil after it has been 
*' aged " f or a year or two. Such oil is known as old tanked oil, and 
gives better results in varnish-making than can be obtained by any 
mere rapid process of bleaching freshly pressed raw oil. 

Oil Repining. 

Purification and Clarification. — The oil obtained from oleaginous 
seeds by pressure is very impure, and owing to the presence of easily 
decomposable foreign substances, amongst which albuminoid prin- 
ciples predominate, it cannot be used in its raw, unrefined condition. 
It must therefore be refined. Mechanical Purification of Oil by 
Filters. — The first stage of the refining process is mechanical^ the 
second, chemical. The oil is purified mechanically by conveying it 
as it comes from the presses into a reservoir, from whence a pump 
distributes it to the filter presses, in which the greater part of the 
foreign substances which it holds in suspension are separated. 
Chemical Purification — Refining, — Chemical purification consists in 
treating the oil, after it has been previously mechanically clarified^ in 
a methodical manner with dehydrating agents such as concentrated 
sulphuric acid. 

By Acids : Thenard's Process. — By using a quantity of not too 
strong acid (1 to 1^ per cent, of 66° B. ; sp. gr. 1'84), the acid exerts 
its action on the foreign matters contained in the oil in preference to 
the oil itself — ^it acts at first by absorbing moisture ; it then attacks 
the foreign matters and transforms them into a carbonaceous mass, 
which imparts to the oil a brown coloration, which, according to 
Livache, quickly deposits as a flocculent precipitate. When the acid 
has completely charred these substances water is turned on to dilute 
the acid, so as to prevent it acting on the oil. After being energeti- 
cally agitated with injection of air, and repeated washing with water 
heated by an open steam pipe, the oil is conveyed into large tanks 
and left to settle. It only remains to separate the purified oil by 
decantation. According to Hartley, however, oil treated in this 
manner is itself frequently charred, or some impurity therein which 
dissolving in the oil imparts thereto a brown coloration, which is not 
removed by the subsequent bleaching process to which the natural 
colouring principles of the oil are amenable. This brown colour in 
his experiments sometimes separated as a flocculent precipitate, but 
only after prolonged subsidence. Success in this process, in fact, 
depends upon adding just enough acid of the proper strength and no 
more as will be sufficient to char the mucilage without attacking 
the oil itself. Hartley states that he succeeded well with acid of 
30 per cent strength (I), which, whilst charring the mucilage, did not 
attack the oil when left in contact with it. 



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16 MANUFACTURE OF VARNISHES. 

[It must be borne in mind that however expert a chemist may 
be, that fact alone does not constitute him an oil refiner, and, as a 
matter of fact, linseed oil can be refined and bleached almost water- 
white by sulphuric acid alone by so-called ignorant workmen who 
have the advantage of being practical.] 

This oil is not, however, free from acid. Linseed oil containing 
even a small proportion of sulphuric acid when heated to the high 
temperature incidental to varnish-making would char. This, of 
course, would be obviated by the use in such a case of a basic drier^ 
such as litharge or manganese, but then only if kept sufficiently long 
in contact with every particle of oil by agitation. Metallic salta 
decomposable by sulphuric acid, such as sugar of lead, would act 
similarly. A very practical method of rapid filtration was given by 
Ure. The filter is composed of three parts, of which the filtering 
material, charcoal, waste, etc., occupies the middle. The oil, placed 
in an adjacent reservoir, communicates on one hand with the lower 
compartment, and on the other hand by a pipe leading from ita 
bottom with a reservoir of water placed at a sufficient elevation. 
The water displaces the oil, and causes it to pass through the filter- 
ing material, and to be transferred into the upper compartment. 

[In these days of filter presses, and working on the large scale^ 
trivial filtering processes like the last two are rather out of date. J 
Those who wish to filter linseed oil on the small scale cannot da 
better than adopt the method used in sugar refineries, where Taylor's, 
filter bags are employed — a wide bag enclosed in a narrow one act- 
ing as a compressing sheath. The apparatus may be enclosed in a 
lead-lined case. Other processes of purifying oils chemically have 
been recommended, such as a concentrated solution of chloride of 
zinc, as suggested by Wagner and recommended by Hartley, heating 
the oil with freshly calcined magnesia ; coagulation of the albuminous 
matter by warm steam pipes, or by the injection of air heated to 
110° C. ; addition of tannin extract or of salts of iron or alumina to 
precipitate albuminous matter; partial saponification with a small 
quantity of caustic lye, so as to carry down the foreign matters with 
the resultant soap in much the same manner as beer is refined with 
isinglass, a process employed with success in the purification of cotton- 
seed oil. Hartley recommends a concentrated solution of sulphate 
of manganese. It would be superfluous to dwell longer upon these 
different processes. This short enumeration will be sufficient. The. 
purified oil is then stored in large reservoirs. 

Bleaching of Oil, — For high-class varnishes it is necessary to use 
a very pale oil. Even with an oil which only shows a very faint, 
yellow tint the quality of the varnish into which it enters will be 
deteriorated. It is therefore necessary to bleach the oil. The 
colouring principles of oils are derived from powerful colouring 
matters existing in the fruits and seeds from whence they have been 
extracted. They may be resolved into four principal substances of 
very similar chemical composition : Xanthophyll and chlorophyll,. 



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OIL CBUSHING AND REFINING. 17 

both yellow, another, but blue, chlorophyll, and finally erythrophyll, 
of a red colour. These substances are not necessarily found in all 
oils, but nevertheless they are always present in linseed oil, and the 
variations in their relative proportions are the cause of the different 
colours which different samples of this oil exhibit. 

If erythrophyll and a mixture of the two chlorophylls predominate 
we get a brown oil ; if a greater proportion of chlorophyll be present 
the oil will have a greenish- brown tint ; finally, if xanthophyll pre- 
dominates a pale yellow oil is the result. These substances are 
decolorised by sunlight, especially in contact with air ; oxidation also 
destroys them; they are also easily decolorised by dilute acids. 
AlkaHes and certain metallic salts first precipitate the chlorophyll, 
then in the long run, if added in excess, the other two substances are 
likewise precipitated ; finally, they are rapidly decolorised by chlorine . 
and hypochlorites. 

Five processes of bleaching oils are in use based upon the pre- 
ceding remarks : (1) By sunlight alone, or by sunlight and air acting 
together; (2) by oxidising agents; (3) by acids ; (4) by alkalies or 
metallic salts ; (5) by chlorine. 

1. Action of Light — In decolorising oil the best result is ob- 
tained by the prolonged action of sunlight, and a superior article 
is said to be obtained to that yielded by the use of chemical 
reagents. This may be true of many chemicals, but not of oil 
refined by sulphuric acid. When linseed oil is exposed in a 
very thin layer to the direct action of sunlight, it bleaches in two 
hours. Working with large quantities the process is of course of 
longer duration, but by using large flasks of colourless glass, saya 
Livache, and exposing the oil in these to direct sunlight, bleaching; 
proceeds very rapidly, and so that the oxygen of the air may aid iik. 
the operation the mouths of the flasks are simply plugged with cottox^ 
wool. When it is desired to treat larger quantities the oil is placed, 
in flat lead-lined or zinc-lined boxes about 40 inches long by 20 
inches wide and 6 to 10 inches deep, covered with a glass plate,, 
and slightly inclined by raising one of the sides of the box about; 
i inch or so ; <or the glass plate is made to overlap the sides of the; 
box, so that no rain-water gains access to the contents of the boxea^ 
which are generally placed in the open air. Finally, two tubes lead 
into the box from the two opposite sides, so that the air on the sur« 
face of the oil is being constantly renewed. Linseed oil, it is said^ 
can thus be bleached to a bright colourless oil in less than a fort- 
night. 

Mulder previously filtered the oil through animal charcoal. Some 
expose the oil to sunlight in contact with animal charcoal for a week 
and do not filter the oil until then. But neither glass flasks nor eveu 
lead-lined boxes, nor, in fact, sim bleaching, whether aided by animal 
charcoal, etc., or not, in any way coincide with the practical notions 
of the present day. Sun-bleaching of oils is only to be found in 
books, and is so long obsolete that any who attempted it on the largQ 

2 

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18 MANUFACTURE OF VARNISHES. 

soale would nowadays be legitimately regarded as crazy. Undoubt- 
edly oil can be bleached almost water- white by the sun when either 
sunlight or daylight can get at it in every direction, but the interest 
on capital more than swallows up the profit, and the market for such 
an article is necessarily confined to artists. 

2. By Oxidising Agents : (a) Peroxide of hydrogen, which is now 
easily obtainable in commerce, has also been recommended. The oil 
is shaken with 5 to 10 per cent, of peroxide of hydrogen of 10 per 
cent, strength. This process would appear to be only adaptable to 
small quantities. Expense would debar its use on the large scale, 
and, as a matter of fact, quite irrespective of expense, both peroxides 
of hydrogen and sodium have no practical value as oil-bleaching 
agents, however energetic they ought to be theoretically in this re- 
spect, and it is only a waste of time, money and patience to attempt 
to bleach oil in this way. 

{h) Ozone. — Attempts have been made to use ozone. It is made 
by causing a current of air to pass through a series of ordinary 
ozonising tubes, where it becomes richer and richer in ozone, being 
finally led to a receiver containing the oil to be oxidised. The oil is 
heated by a steam coil to about 40"" to 50° C, and the ozonised air is 
admitted to the bottom of the vessel, and is made to pass through 
the whole of the oil by means of a tube pierced with very small holes. 

Schrader and Dumcke found that ozone only acts upon the oil for 
a comparatively short time — ^it in fact stops very quickly. But if the 
oil thus treated be placed in white glass flasks in flat boxes, in con- 
tact with air and preferably in the sun, the action continues of its 
own accord, bleaching and thickening the oil in a very short time, 
and causing it to dry much more rapidly. 

Although information and particulars in regard to the bleaching 
of oils by ozone are far from definite, this process, says Livache, ought 
to receive the attention which it undoubtedly deserves. But so long as 
there are so many adventurers in the field, gUb of tongue and adepts 
in persuasion, who simply hve by imposing on those in the trade 
desirous of testing new methods in a rational manner, so long will 
such methods as bleaching by ozone be highly discounted. Each 
adventurer is more anxious than another to trap the unwary manu- 
facturer. It is not the adventurer's wish, even if he were capable of 
bringing any such process to a successful issue, that it should 
succeed. His hving would then be gone. His poUcy, before the 
final grand test which is to show such grand results, is to goad his 
patron on to a quarrel, as a result of which he leaves to trap some 
other unwary manufacturer, a rival in trade of the one he has just 
left, and who is only too ready to listen to any story of the expert's 
{sic) unjust treatment at the hands of his rival, and so he proceeds 
from factory to factory in his successful confidence-trick method of 
exploiting his process, and so the game goes on until it is naturally 
played out, when he finds some other fortune in less-than-no-time- 
making process to exploit in the same way, unless, perchance, in the 



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OIL CRUSHING AND REFINING. 19 

interval he has not come to an untimely end in some more than 
usually rash and ill-advised experiment. 

(c) By Permanganate or Bichromate of Potash, — The perman- 
ganate, or, better still, the bichromate of potash, in conjunction with 
sulphuric acid, have long been used as bleaching agents. The pro- 
cess is conducted in wooden tanks lined with lead. For every 100 lb. 
of oil about h lb. of bichromate of potash is mixed with double its 
weight of sulphuric acid, previously diluted with five times its bulk 
of water. This mixture is run into the oil in a thin stream, with 
constant stirring, which is kept up for an hour, the oil, if need be, 
being heated all the time by a steam coil. The hquids are allowed 
to separate, the lower layer drawn ofif, and the oil repeatedly washed 
with hot water. This process is tedious, owing to the difficulty of 
eliminating even by acid the green hydrated oxide of chromium 
which dissolves in the oil. The same remark appHes to bleaching 
with manganese compounds where a similar hitch occurs. There is 
a great loss of oil with both processes altogether incompatible with 
the extent of any to which the oil may be bleached. However, in 
both cases the oil may increase in drying properties owing to the 
action of the nascent oxygen developed in the processes in question. 
By lAnoleate of Manganese, — Blenkinsop and Hartley (see p. 32) pro- 
posed to bleach linseed oil, or rather to produce a ** boiled " oil paler 
than " raw " oil, by oxide of manganese introduced in the state of 
linoleate of manganese dissolved in coal-tar naphtha. The process 
involves the use of heat. The oxygen used up in oxidising the oil and 
bleaching the colouring matters is restored to the manganese by a 
current of air as fast as it is deprived of it. But this process was well 
known both in Britain and America long before the date of this patent. 

3. By Acids: (a) By Nitric Acid, etc. — Lawson has suggested 
dilute nitric acid. The process should be most carefully watched, so 
as to prevent any elevation of temperature. In England, according 
to Livache, use is made of a mixture of nitric acid and chlorate of 
potash in the proportion of 1 to 2 per cent, of the oil to be decolorised ; 
heat is applied, and the oil is then repeatedly washed with water. 
This process, he says, has been successfully employed with cotton- 
seed oil, but as a matter of fact the caustic soda method for refining 
cotton-seed oil and the sulphuric acid method for refining linseed 
reign supreme in Britain, and this is in accordance with the fact that 
it is principally coloured mucilaginous impurities which have to be got 
rid of in refining linseed oil, whilst it is coloured resinous impurities 
which are present in crude cotton-seed oil. 

(b) Svlphu/ric Acid, see pp. 16-16. 

4. By Alkalies and Metallic Salts : (a) By Caustic Soda, — Certain 
oils, containing resinous colouring principles, particularly cotton-seed 
oil, may be completely decolorised by agitation with a small quantity 
of coAJbstic potash or soda (1 per cent,). Combination with the 
colouring principles ensues, and as a result these aria precipitated as 
cotton-seed oil foots, from which the purified oil may be easily run off 



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20 MANUFACTURE OF VARNISHES. 

through a syphon or otherwise. It is not applicable to linseed oil — 
at least to the same extent. 

{b) By Carbonate of Potash. — 5 lb. of the carbonate dissolved 
in 10 gallons of water are added to 100 lb. of oil, and the mixture 
stirred to thorough incorporation ; 2^ gallons of a 2 per cent, solution 
of chloride of calcium are then added. The oil bleaches rapidly, and 
it is then decanted and treated with a 5 per cent, solution of sulphuric 
acid, and afterwards washed until perfectly neutral. But this would 
be far too laborious and expensive a process for adoption on the large 
scale, and like others has nothing to recommend it over the sulphuric 
acid process. 

(c) By Ferrous Sulphate : Artists* Oil — Amongst the salts pro- 
posed, ferrous sulphate (green vitriol) is capable of giving good results^ 
with small quantities of oil. Process, — One part of green vitriol is 
dissolved in li parts of water, and this mixture is added to double its 
volume of linseed oil contained in a glass flask. The whole is then 
exposed to sunlight, and shaken at least once a day. The oil is 
generally bleached in from three to six weeks, according to ijie 
amount of sunshine. When the oil is decanted the green vitriol 
solution can be used over again for treating a fresh quantity of oil. 
This process is much in vogue with artists' colourmen (the bleached 
oil being sold as artists* oil), but is too tedious, laborious and costly 
for adoption on the large scale. 

(d) By Basic Acetate of Lead. — A solution of basic acetate of 
lead when agitated with oil eliminates its colouring principles very 
effectually. 

(e) By Sulphate of Lead, — This process also gives good results. 
It is mixed with the oil to the consistency of cream, and exposed as 
in the preceding process to sunlight, with frequent agitation. After 
a time the oil is bleached. Two layers are found at the bottom of 
the flask, one consisting of sulphate of lead, the other of colouring 
matter. The sulphate of lead may be used over again. The rationale 
of the process is obscure. It may to a certain extent be looked upon 
as similar to the clarification of beer by isinglass. 

(J) By Complex Mixtu/res, — More or less complex mixtures of 
different metallic salts are also used. We will only name the follow- 
ing, which gives good results, without seeking to demonstrate the 
precise reactions which simultaneously occur. To 10 gallons o£ 
linseed oil are added 1^ gallons of water, containing ^ lb. of black 
oxide of manganese, ^ lb. of bichromate of potash, ^ lb. of carbonate 
of soda and ^ lb. of common salt. The boiling solution is added to 
the oil ; it is left to clarify, and the colourless oil is decanted. 

5. By Chlorine. — Substances from which chlorine can be gene- 
rated without the aid of heat are added to the oil. For instance, 5 
lb. of concentrated muriatic acid, 33 per cent., diluted with four 
times its weight of water, are added to 10 gallons of oil. The whole 
is well stirred, whilst a solution of 1 lb. of bichromate of potash in. 
1 gallon of water is added. A mixture of red lead and hydroohloria 



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OIL CRUSHING AND REFINING. 21 

acid may also be usecL To 10 gallons of oil i lb. of red lead beaten 
up with ^ lb. of oil is added, and the whole well stirred, whilst i lb. 
of hydrochloric acid is added. During the next five days an addi- 
tional J lb. of hydrochloric acid is added daily, the whole being well 
stirred several times during the twenty-four hours. The decanted oil 
is run into large bottles, or placed in boxes lined with lead, and ex- 
posed to sunlight until the oil is perfectly colourless. 

Summary, — The most rapid method of bleaching oils, according 
to Livache, is by means of chemical reagents, especially chlorine, 
but it must not be forgotten, he adds, that it is difficult to free the oil 
from all trace of these reagents, which in the end may exert a vexa- 
tions and injurious influence upon the final products manufactured 
from an oil bleached in this way. As a matter of fact, chlorine does 
not bleach linseed oil, it darkens it. Certain bleaching agents, like 
chlorine and nitrous acid, are apt to form substitution compounds 
which alter altogether the nature of the oil, and not for the better. 
Had one space at his disposal, and a sufficient supply of refined oil 
to meet his wants in the meantime, says Livache, the bleaching 
of oil by means of sunlight in flat boxes covered with glass plates 
cannot be too highly recommended. The slowness of the process 
would, he says, be largely compensated by the beauty and quality 
of the products manufactured from such an oil. 

However that may be, an equally good product can be obtained 
by bleaching with sulphuric acid in fewer hours than it takes weeks 
by sunlight. In fact, bleaching by sunlight could only be recom- 
mended by those who have never seen oil refined by sulphuric acid, 
which is the most effectual, the most expeditious and the most eco- 
nomical process, requiring no costly plant, no costly chemicals, only 
about 1 lb. of oil of vitriol per 10 gallons of oil. A steam pipe heated 
by exhaust steam mixes the acid and oil together, and does aU the 
agitation necessary for washing the acid out of the oil, all the opera- 
tions being done in the one tank if need be. No process could be 
cheaper, no process could be more simple, but it requires care and 
experience, as it is quite easy to irretrievably spoil 5 to 10 tons of oil 
which can then only be used for boiled oil. 



Note. — Ea^lanation of Fig. 9. — ^The solvent distilled from B ascends right 
tube of A into condenser, K, from which it falls on to weighed amount of material 
to be extracted in the wide central tube of A, from which, charged with oil, it 
runs off automatically through left syphon tube into B, whence it is redistilled, 
and so the cycle goes on until the material is exhausted of oil, when the flask is 
detached, the ether distilled off, and the residual oil weighed. 



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CHAPTEE II. 
OIL BOILING— THEORETICAL AND PRACTICAL. 

Chemical Constitution of Drying Oils. 

Linolein, — Since all oils consist of carbon, hydrogen and oxygen 
in almost identical proportions, it may well be asked what principle 
it is that is present in certain oils and causes them to dry, and which 
must therefore be absent in those oils which do not dry. Mulder 
found that the principal constituent of Unseed, poppy-seed and wal- 
nut oils — as well as that of all drying oils — was linolein, a substance 
formed by the combination of linoleic acid with glycerine. His 
conclusions have been partially confirmed by Hazura and Friedreich, 
who found, in poppy-seed and walnut oils, fatty acids analogous to, 
if not identical with, linoleic acid. More recently, however, as a 
result of fresh experiments, Hazura has been led to regard linoleic 
acid as composed of two distinct acids, linolic and linolenic. But 
Eeformabsky disputes these conclusions. As a consequence of still 
more recent researches by Livache (Comptes Bendus de VAcadimie 
de SciencBy 1896), he holds that the theory that the drying properties 
of linseed oil are entirely due to the presence of linolein can hardly be 
maintained. In fact all other oils, whether of yegetable or animal 
origin, are capable of being transformed into a sohd product analogous 
to that to which hnseed oil is so easily converted, and that whether 
taken individually or as the component parts of a mixture, provided 
always that they be submitted to the action of heat. But actual 
facts are against any such conclusions ; no amount of heating or 
treating with driers will ever make castor oil ** dry ". It is true the 
oil may be converted into a plastic solid by heat and driers, but, 
however useful such a substance might be as a pitch substitute, it is 
of no value as a drying oil; non-drying oils rancidify but they do 
not dry. According to the present state of our knowledge of this 
subject, continues Livache, it seems that the best explanation that 
can be given of the drying properties of oils is the following: All 
the different glycerides which enter into the composition of a drying 
oil play a part in the transformation of the oil into a solid body, but 
the greater the proportion of one or several glycerides analogous to 
linolein the more rapidly is this transformation effected, and at a 

(22) 

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OIL BOILING — THEORETICAL AND PRACTICAL. 23 

lower temperature. All the glycerides present in oils and fats under- 
go this change more or less slowly, as if by a kind of metamorphosis. 
Neither can this doctrine be upheld. It is ridiculous to say that the 
stearine of cotton-seed oil plays any part in drying but a negative 
one. Looking at the matter from this standpoint, we are able to 
explain the differences — in drying properties — of different drying oils. 
Should in fact the glycerides, analogous to linolein, be present but 
in small quantity, we can understand that the other glycerides will 
only dry slowly, and very often we must resort to the aid of heat to 
accomplish the object in view. Whatever explanation we adopt, we 
must bear in mind that the drying oils are those which may be 
quickly converted into a solid elastic substance at the ordinary tem- 
perature. This transformation can only take place in the presence 
of oxygen, and with a rapidity which varies much according to the 
heat and light the oil is exposed to, and the previous treatment to 
which it has been subjected.. 

Linoxin. — In the case of linseed oil Mulder called the resulting 
solid product linoxin. He found that it did not differ from linoleic 
acid but by containing a larger proportion of oxygen, whilst at the 
same time all the glycerine had disappeared. While making reser- 
vations necessitated by the still imperfect state of our knowledge 
regarding the composition of the different solid bodies obtained by 
the oxidation of different oils, we shall retain the name of linoxin, 
for this body, no matter what oil it may be derived from, presents 
the same properties of elasticity, insolubility in the usual solvents, etc., 
etc. Linoxin consists of a perfectly dry elastic mass, of a more or less 
deep yellow or brown colour according to the treatment the oil from 
which it has been derived has been subjected. For a long time it 
was believed to be perfectly insoluble in the different menstrua in 
which oils dissolve. When exposed to their action it at first under- 
goes no change, but if the action be prolonged it increases in 
transparency, swells like indiarubber, and at the same time a small 
proportion dissolves. The resulting swollen substance dried apart 
from the solvent is still elastic, but very friable between the fingers, 
crumbling to particles, with no tendency to reunite. By evaporating 
the solvent there is left a tacky residue of low melting-point. The 
oxidation product of a drying oil, therefore, presents many analogies 
to caoutchouc, being composed like it of two constituents, one of 
which dissolves in different menstrua, whilst the other swells and 
disintegrates. The dissolved product recovered on evaporation of 
the liquid solvents acts as a real cement, reuniting the insoluble 
portions, first swollen and then disintegrated, yielding as a result a 
continuous, elastic mass, consisting on the one hand of the soluble, 
and on the other hand of the insoluble, portion of the original linoxin. 
But very possibly this liquid portion found by Livache was simply 
incompletdy oxidised oil. Thus before an oil can dry, the linolein 
must be in a position to become oxidised, and the more this is 
facilitated the quicker does the oil dry, as the oxidation of the other 



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24 MANUFACTURE OF VARNISHES. 

glycerides would appear to be one of the functions of the oxidation 
of the linolein. 

Oxygen may be caused to act either upon the linolein, i,e., upon 
linoleic acid combined with glycerine, or upon the linoleic acid 
separated from glycerine, or finally. upon suitable chemical com- 
binations of linoleic acid with metallic oxides, i.e., upon linoleates. 

Action of Oxygen upon Linolein. — Linseed oil exposed to the air 
in a thin layer soon changes to a solid substance. If we perform 
the same experiment in a vessel containing air placed mouth down- 
wards over mercury, the same change takes place, but the volume of 
air confined over the mercury diminishes in volume owing to the 
absorption of oxygen. Finally, if the quantity of air suffices, the oil 
is converted into a solid product which has increased in weight pro- 
portionally with the oxygen which existed in the air and which has 
disappeared, whilst the residual gas is composed of nitrogen, together 
with a small quantity of carbonic acid, and volatile acids of the 
methane series. The transformation of the oil and consequently of 
the linolein is thus due to the action of oxygen. Mulder obtained 
this soHd body by exposing the oil on plates to the action of the air, 
and after detaching, he treated the product with ether, alcohol and 
water so as to wash away any unoxidised oil or other soluble matter ; 
and he finally obtained a more or less elastic white substance which 
analysis showed to be a product of the oxidation of the anhydride of 
linoleic acid, viz,, linoxin. From linoleic acid exposed in a thin layer 
to the air he obtained the same solid linoxin, but the change into a 
perfectly dry substance took longer than in the case of linolein. But 
the products are identical in composition and properties, and as no 
glycerine is found in the product of the oxidation of linolein by the 
air, it would appear that the oxygen of the air first acts upon the 
glycerine, yielding such bodies as carbonic acid, water, etc., which 
disappear, and then upon the linoleic acid of the linolein, converting 
it into a solid body, Unoxin. The product is identical whether we 
use air or oxygen. Effect of (1) Heat and (2) Light and (3) Different 
Bays on Bapidity of Drying, — (1) Heat exercises a very decided in- 
fluence ; oxidation takes place more rapidly, whilst at the same time, 
the oil being more fluid, the oxidation is more thorough owing to 
the oxygen penetrating the oil better and more deeply. Every one 
knows that paint and varnish dry better in summer than in winter. 

(2) The intensity of the sun*s rays has a very decided action. Oil 
exposed to direct sunlight dried in four days, whilst the same oil in 
similar circumstances, but in semi-darkness, took fifteen days to dry. 

(3) According to Cloez, when the light is caused to pass through 
coloured glass the oxidation varies with the colour. The maximum 
amount of oxidation takes place with colourless glass, but with blue, 
red, green, or yellow, a longer time is required the nearer the colour 
approaches to yellow. (4) When oil is exposed to air in darkness, it is 
longer before the oxidation process sets in, and it takes a very long 
time for complete oxidation. 



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OIL BOILING — ^THEORETICAL AND PRACTICAL. 25 

Action of Oxygen upon Lmoleates. — Linolein is very easily sap- 
onified, yielding soaps ; potash, soda and ammonia yield soaps which 
xeadily dissolve in water. Baryta, Hme, the oxides of zinc, copper 
and lead, yield soaps insoluble in water but soluble in ether. The 
most suitable combination to study is that of linoleic acid with oxide 
of lead; if we dissolve this linoleate of lead in ether, and if we 
•expose the Hquid in a thin layer upon a plate of glass, the white 
i9olid residue remaining on evaporation of the ether, which is at first 
floft, becomes in a few days very hard, owing to the absorption of 
oxygen. 

Linoxic Acid, — If we suspend this hard, brittle salt of lead in 
idcohol, and pass a current of sulphuretted hydrogen through the 
alcohol, we obtain, after filtering ofif the sulphide of lead, an 
alcoholic solution from which water precipitates a white substance, 
which analysis shows to be that oxidation product of linoleic acid 
to which the name of linoxic acid has been given. If instead of 
separating this alcohol in the cold by the simple addition of water, 
we evaporate the alcoholic solution by the aid of heat, we also obtain 
a viscous residue, but of a blood-red tint. Linoxic acid is therefore 
met with in two colours — white or red — according ais it has been 
prepared in the cold or the hot state, i.e., whether hydrated ot 
anhydrous. But whilst viscous linoxic acid exposed to the air changes 
*o dry elastic linoxin, on the contrary, when combined with lead — 
although it also sufifers this alteration — it becomes more and more 
friable. 

B4su7n4, — (1) Linoleic acid combined with glycerine, in the 
state of linolein^ yields progressively in a more or less short period 
of time linoxin, a solid elastic body, a basis for colours and 
varnishes. (2) Free linoleic acid yields fairly quickly a viscous 
compound (linoxic acid) which afterwards changes to linoxin, but 
after a longer period of time than in the preceding case. (3) 
Linoleic acid combined with oxide of lead, i.e,, linoleate of lead, 
dries fairly rapidly in consequence of the formation of linoxate 
of lead, but this product changes afterwards into a friable, brittle sub- 
stance. It follows that, to ensure a dry, elastic product, we ought 
preferably to cause the oxygen to act upon the linolein and to avoid, 
as far as possible, either the presence of linoleic acid, which would 
take a longer time to dry, remaining viscous for rather a long time 
in consequence of the formation of linoxic acid, or an excess of 
linoleate of lead, which would give a brittle, friable product. Owing 
to the difficulty of separating Hnolein from the other principles en- 
tering into the composition of oils in actual practice, we have to 
oxidise the oil itself. The drpng properties of a drying oil are 
increased under certain conditions, which it is important to study 
in detail. We shall study, therefore, how the drying properties of 
linseed oil — the best drying oil — may be increased, for whatever we 
may determine regarding it holds good, keeping to the same propor- 
tions with other drying oils. 



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26 MANUFACTUBE OF VABNISHES. 

Methods of Increasing the Drying Properties of a Drying OU. — 
The rapidity of drying is influenced by : (1) The degree or extent to 
which the oil has been refined ; (2) the time which has elapsed 
since its extraction; (3) the conditions under which it has been 
preserved ; (4) heat ; (5) addition of certain substances. 

1. Extent to which Oil has been Bejined, — The oil as it issuea 
from the press contains water and impurities, mucilage ** foots *\ It 
is evident that to obtain a continuous elastic mass, it would he 
advantageous to get rid of these substances by allowing the oil to 
clarify itself by simple deposition, by filtration, or by chemical treat- 
ment In the latter case, the oil is generally treated with sulphuric 
acid, which frees it from substances which play no part in the 
drying of the oil, because they do not fix oxygen ; if we expose to the 
air comparatively freshly pressed oil, and the same oil, after treat- 
ment with sulphuric acid, then freed by washing with hot water from 
all trace of acid, we find that the oil in the second case absorbs a 
larger quantity of oxygen. Moreover, the paler the oil the whiter will 
be the final product, i.e,, the dried coat of Hnseed oil thus demonstrate 
ing that the oil ought to be bleached before application. 

2. Age of the Oil. — Oil preserved from contact with the air 
absorbs oxygen the more rapidly the longer it has been stored, owing 
possibly to a polymerisation of certain principles of the oil. Fahrion 
thinks that the non-saturated fatty acids enter into combination with 
themselves to form complex addition products. 

3. Method of Storing the Oil. — Leaving age out of account, if the 
oil has been stored in contact with air it will already have absorbed 
a certain quantity of oxygen. Now experience shows that if, in the 
beginning, the oil absorbs oxygen rather slowly, this absorption, once 
fairly started, goes on afterwards much more rapidly. In the case of 
such an oil the absorption of oxygen will take place much more 
rapidly when applied to any surface exposed to the air. 

4. Action of Heat. — The temperature at which an oil is exposed 
to the air has an influence on the rapidity of drying of that oil. Linseed 
oil dries more rapidly at a temperature of 25° to 28° C. than at a 
temperature of from 15° to 18° C. (Chevreul). Filrther, if we expose 
raw linseed oil under the same conditions of temperature to the action 
of air, and the same oil, after having been previously submitted to the 
action of heat, the drying property is altered. If we heat linseed oil 
for three hours, so that it only disengages a few gaseous bubbles 
from time to time, the drpng properties of the oil are greatly in- 
creased ; as has been shown by Chevreul, it takes only about half 
the time to dry. Fahrion states that when boiled in a deep pan, so 
that oxygen of the air cannot intervene to any great extent, the 
polymerisation of the non-saturated fatty acids is accelerated with 
the formation of complex substances which absorb oxygen more 
rapidly ; a very unreliable statement. But Chevreul found by pro- 
longing the heating of the oil — the temperature, etc., remaining con- 
stant — that oil heated for five hours took longer to dry than oil heated 



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OIL BOILING — THEORETICAL AND PRACTICAL. 27 

for only three hours. It is probable that under the influence of pro- 
longed heating a certain proportion of the glycerine is destroyed (as 
the smell of acrolein would appear to indicate) with the simultaneous 
liberation of Hnoleic acid. We have seen that linoleic acid takes 
longer to dry than linolein, which probably explains why Mulder 
found that oil heated to between 70° and 100° C. took longer to dry 
than raw oil. What we can say is that : (1) A regulated temperature 
stimulates the drying properties of raw oil ; (2) exposed to the same 
temperature raw oil dries less quickly than when it has been pre- 
viously submitted to the action of heat, provided always that the 
heat is regulated so that the oil does not decompose in such a way 
as to hberate free linoleic acid. 

5. Addition of Certain Substances : Driers. — White lead, litharge, 
black oxide of manganese, etc., stimulate the drying properties of eu 
drying oil. Sometimes these substances may be added in the cold, 
sometimes the mixture is heated. The process of oil boiling in most 
general use is that in which the oil is simply heated with a lead com- 
pound. The increased drying properties of the oil have by some been 
attributed to the formation of linoleates of lead with the simultaneous, 
production of free hnoleic acid on heating, whilst others aver that the 
oil becomes oxidised at the expense of the hnoleate of lead, as borne 
out by the fact that a certain proportion of metaUic lead is found at 
the end of the operation. This double explanation is not satisfactory 
for the following reasons : because linoleate of lead only imparts a. 
fictitious drying property it very soon becomes brittle and friable, 
whilst, on the other hand, linoleic acid dries less quickly than 
Hnoxin. It is, however, an incontestable fact that an oil heated with 
oxide of lead dries quicker than raw oil, or oil heated by itself alone. 
The question then is whether the oil increases in drying properties- 
at the expense of the oxygen of the oxide of lead. 

Again, good linseed oil exposed to the air absorbs 16 to 18 per 
cent, of its weight of oxygen before it dries completely, and on the 
other hand, as the quantity of oxide of lead, litharge or red lead does- 
not exceed 3 to 8 per cent., at the highest estimate, of the oil to be 
boiled, it will be seen that the amount of oxygen which this oxide of 
lead could yield would be less than 1 per cent, instead of the 16 to 
18 per cent, which is necessary, and consequently that it can only 
play a very secondary part as far as the direct oxidation of the oil is- 
concerned, much more so as a part of this oxide does not yield up any 
of its oxygen to the oil. Yet a certain quantity of metaUic lead left 
at the end of the operation proves that a corresponding quantity of 
oxygen has started the oxidising process, and we have seen, in study- 
ing the action of oxygen upon raw oil, that the drying propertiea 
of an oil increase more rapidly after the oil has reached a certain 
stage of oxidation. But the remarkable increase in drying pro- 
pensities altogether out of proportion to the oxygen equivalent to the 
reduced lead proves that this reaction would in any case appear to be 
of a secondary nature. The same objections and the same explana- 



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28 MANUFACTURE OF VARNISHES. ^ 

tions hold good in regard to the function of manganese compounds 
as driers. 

It was for a long time imagined that during boiling the oil was 
oxidised and its glycerine decomposed, but analysis of boiled oil 
shows that it still contains almost the whole of its glycerine, and 
this is as it should be, for linoleic acid dries much more slowly than 
linolein. The theory of the driers acting as oxygen carriers is only 
Tcry partially, if at all, true, as oxidation is shown by analysis not to 
take place to any considerable degree. Moreover, the iodine value 
of the original oil is not diminished to any great extent even when 
"the oil has been treated by ozone. If the oil were oxidised to any 
extent the iodine values would be correspondingly lowered. 

Influence of Surface on Bapidity of Drying, — But Chevreul gives 
a better explanation. He showed that if we spread Hnseed oil on 
lead foil, freed from all traces of oxide, the drying quaHties of the oil 
increase greatly. The oil cannot in this case absorb any oxygen but 
what the air can in the normal state of the oil supply. The greater 
rapidity of drying can only therefore be attributed to the presence of 
the metal, leaving out of account the combination in which it may 
■enter the oil [But neither Chevreul nor Livache take into account 
the action of free fatty acid on metallic lead, so this experiment of 
ChevreuFs proves nothing, but that the oil contained or developed 
free fatty acid, and that this free fatty acid attacked the lead, and 
that the oil dissolved the resulting nascent linoleate of lead, and thus 
hastened the oxidation process.] 

But we may go further, continues Livache. If we shake raw oil 
with very porous metallic lead — obtained by precipitating a salt of 
lead by another metal — in a flask deprived of air, we find that, with- 
out applying any heat whatever, the oil dries much more quickly 
than before treatment, and in this case it is certain that there has 
not been any oxygen supplied to the oil. The only certain modifica- 
tion which the oil has undergone is the presence of a small proportion 
of lead, and we are thus led to conclude that the reason the oil 
dries quicker is due solely to the presence of this small quantity of 
lead. But here again Livache omits the one important point, the 
action of the fatty acids invariably present in the oil, and which will 
act much more rapidly on finely divided lead. In the case of man- 
ganese we cannot avail ourselves directly of this experiment, but by 
an artifice we can place the oil in the same conditions with regard to 
manganese. The oil is previously treated with the precipitated lead, 
then with a solution of a salt of manganese, the sulphate for example, 
which by double decomposition will yield sulphate of lead insoluble in 
ihe oil, whilst at the same time the manganese takes the place of the 
lead. It has thus been found that the resultant oil dries quicker, 
better even than that obtained by heating raw oil with a manganese 
salt. It is by studying the action of a manganese-treated oil that an 
'explanation has been found of the cause of the increase in drying. 
If we spread such an oil in a thin layer in contact with air, it will 



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OIL BOILING — THEORETICAL AND PRACTICAL. 29 

assume a brown tint, due to the passage of the oxide of manganese 
present to a higher degree of oxidation owing to the absorption of 
oxygen from the air, but this brown coloration fades as the oil be- 
comes more viscous, finally disappearing altogether. The oxygen of 
the peroxide of manganese is used up in oxidising the oil, and in the 
end a perfectly colourless solid mass is obtained. 

This coloration, followed by complete decoloration, shows that the 
oxide of manganese has played the part of an intermediary or carrier 
of oxygen, becoming easily peroxidised, and afterwards giving up its 
excess of oxygen to the oil. The action of oxide of lead is probably 
similar but less energetic. We are, in fact, face to face with one of 
those phenomena, the inference to be drawn from which has been 
defined by M. Berthelot as follows: "We see by these phenomena 
how latent energy, and energy capable in theory of produLcing exother- 
mal phenomena^ but which under given circumstances do not produce 
such phenomena, maybe rendered manifest by the intervention of 
certain agents acting solely as intermediates or go-betweens, and 
capable of developing reactions which may go on indefinitely. This 
is the foundation of the whole theory of thermochemistry as enun- 
ciated by me in 1865 " (" Action by Presence," Comptes Bendus de 
VAcad^rme de Science, 1889, t. 109, p. 646). In a Utharge or man- 
ganese-treated oil the lead or the manganese plays the rdle of inter- 
mediaries, taking the oxygen from the air and giving it up to the oil, 
which becomes oxidised more rapidly than without the aid of these 
intermediaries, and this reaction goes on to a certain extent during 
boiling, but when the oil is exposed to the air on a given surface it 
only ceases when the layer of oil has absorbed its maximum of 
oxygen. The catalytic action of the drier is not brought into full 
play until the oil has been exposed to the air in the form of the 
usual thin coat of paint or varnish. Vincent also defined this- 
action as catalytic, but only as far as manganese was concerned. 
In virtue of the fact that both rosinate and linoleate of manganese 
dissolve in the oil, Vincent's hypothesis requires modification. Lith- 
arge and lead salts in his opinion dissolved in the oil, and thus- 
intensified its drying properties, whilst manganese salts simply acted 
as carriers. 

To find whether other metals could perform the same function a& 
lead and manganese, a litharge- treated oil was stirred with a salt of 
the different metals to be tested, the acid of which would give with 
lead a salt insoluble in the oil. Livache found that litharge-treated oil 
spread on a glass plate dried in twenty-four hours, when manganese 
replaced the lead in six hours, whilst, when the lead was replaced by 
copper, zinc or cobalt, the oil took thirty to thirty-six hours to dry^ 
and finally the oils in which lead was replaced by nickel, iron, chrom- 
ium, etc., did not dry completely until after forty-eight hours. A 
very important point, says Livache, to be borne in mind is the fact 
that an oil indirectly treated with manganese by the substitution of 
manganese for the lead of a litharge-treated oil dries much faster than 



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30 MANUFACTURE OF VARNISHES. 

an oil directly treated with manganese. But it is very difficult to see 
why this should be so. 

Lead and Manganese Salts, — ^Besides the oxides of lead and man- 
ganese we may employ certain salts of these oxides. But their 
choice would appear to be subordinate to their degree of solubility in 
the oil, and to the way they behave when heated along with the oil. 
Further, all the numerous salts proposed have been discarded except 
the acetate (sugar) of lead and borate of manganese, and the reason 
is not far to seek. These salts decompose when heated, and yield as 
a final result either the oxide of lead or finely divided metallic lead, 
or oxide of manganese, of which the valuable function is well known. 

1. Acetate of Lead, — This salt melts in its water of crystallisation 
at about 75° C. Above 100° C. it loses water and a little acid, yield- 
ing the sesquibasic acetate, which towards 280° C. is completely 
decomposed, giving off carbonic acid and acetone and leaving as a 
residue metallic lead in an extremely fine state of division (spongy 
lead). We have seen the important r6le this plays in stimulating the 
drjdng properties of oil. 

2. Borate of Manganese, — Again, on the other hand, we have in 
borate of manganese a very unstable salt, as is the case with borates 
in general. The affinity of boracic acid for oxide of manganese being 
but very feeble, the latter is liberated by the action of heat ; the em- 
ployment of this salt is therefore a useful roundabout way of introduc- 
ing oxide of manganese into the oil. 

As non-oxidised metallic lead, in a very porous condition, increased 
the drying properties of the oil, it was interesting to study the action 
upon oil of other metals capable of being easily precipitated. But 
the oil dried no quicker when treated with precipitated tin or copper. 
Besides, these results might have been foreseen, for Chevreul showed 
that linseed oil, spread upon well-polished lead, dried much more 
rapidly than when spread upon copper, brass, zinc or iron. With 
these metals the oil did not dry any faster than upon plates of glazed 
or unglazed porcelain, glass or plaster of Paris. As to the numerous 
other substances besides the salts of manganese and lead proposed to 
be added to drying oils to hasten their drying properties, none of 
them appear to exert any beneficial influence. Chevreul made a 
comparative study of the oxides of zinc and lead and showed that the 
former had no appreciable influence, and that certain substances even 
acted in a contrary manner, retarding instead of hastening the drying 
of the oil, such as the oxide of antimony and antimonious arseniate. 
If certain substances appear to act as driers, the reason is to be foimd 
in the fact that they have been used in conjimction with the applica- 
tion of heat, and their apparent beneficial action is due to the heat 
alone. According to And6s the following substances may be regarded 
as absolutely useless : all organic matters (sepia, dog excrement, bread, 
onions, garHc), red oxide of mercury, verdigris, lime, brass, zinc, alum, 
hydrated oxide of iron, boracic acid, oxide of antimony, gypsum, ver- 
milion, pumice-stone, animal charcoal, and the following as Oxidising 



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OIL BOILING — THEORETICAL AND PRACTICAL. 31 

Agents, — White lead, sulphate of lead, carbonate of lead, basic acetate 
of lead, black oxide of manganese, hydrate of protoxide of manganese, 
sulphate of zinc, oxide of zinc, umber, and those in this final list as 
Energetic Oxidising Agents. — Air — acting through its oxygen — red 
lead, litharge and the different oxides of lead, borate of manganese 
a.nd the hydrated peroxide of manganese. 

Becently Kastner has proposed the plumbates of the alkaline 
-earths as driers. These are prepared by heating in a suitable furnace 
two molecules of baryta, strontia or hme, or their corresponding car- 
bonates with one molecule of oxide of lead. The plumbate of baryta 
is dense black, that of strontia, brown, and that of lime, bright red. 
Kastner is of opinion that the drying property of the oil is increased 
by the richness in oxygen and the introduction of lead; he holds 
further that the introduction of the alkaline earths themselves may 
produce oleates, which after drying assume a consistency of remark- 
able elasticity. We ought therefore to confine ourselves in the use of 
driers to lead and manganese^ to their oxides^ and in certadn cases to 
some one of their salts. 

Catalytic Action of Driers, — An experiment of Chevreul lends 
support to the theory of looking upon manganese and lead as simply 
performing the function of intermediaries or oxygen carriers, viz. : 
If we make a mixture of raw linseed oil and manganese-boiled oil, 
the liquid resulting from this mixture has a much greater oxygen 
absorbing power than either of the liquids constituting the mixtures 
taken separately. 

If this be true, then a pale boiled oil made by diluting a manganese 
boiled oil with raw oil ought to be a very desirable mixture indeed. 

It follows that the quantity of oxygen absorbed during the same 
period of time is not proportional to the quantity of oxide of man- 
ganese contained in the oil, since the boiled oil reduced with raw oil 
absorbs more oxygen, although bulk for bulk it contains less oxide 
of manganese than the original manganese-boiled oil. The only 
feasible explanation is this : If the raw oil in the mixture absorbs 
a greater quantity of oxygen in the same space of time, it is simply 
because this oxygen is suppUed -to it under more favourable con- 
ditions. Now these conditions are precisely the fixation of oxygen 
by the oxide of manganese, which forthwith gives it up to the oil ; 
there is thus a continual transport of oxygen from the air to the 
manganese and thence to the oxidisable principles of the oil. 

It seems, therefore, that an oil will dry in a better manner the 
less metallic linoleate it contains, because linoleate of lead absorbs 
less oxygen than linolein and becomes brittle ; all we have to do is to 
introduce a quantity of lead or manganese sufficient to extract from 
the air the quantity of oxygen necessary to oxidise the linolein as 
fast as this oxidation proceeds. A large quantity of lead or man- 
ganese does not hasten the oxidation — ^the intensity of which is the 
sole function of the drying quality of the oil used — but would on the 
contrary yield a less elastic and slower forming final product. Again, 



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32 MANUFACTURE OF VARNISHES. 

summing up the proper conditions under which the drying properties 
of an oil are stimulated we can deduce the following principles : (1) 
The oil ought to be refined and clarified ; (2) there is an advantage 
in allowing the oil to age before using it ; if need be, oxidation may 
be started ; (3) it is more preferable to use boiled oil than raw oil ; 
(4) the drying of raw oil or boiled oil is hastened by the addition 
of either lead or manganese compounds in known quantities, or by 
metallic lead in a fine state of division. It remains to consider how 
in actual practice we can conform to the principles enunciated. In 
actual practice the oxides of lead and manganese or their salts are 
preferred ; nevertheless the use of metallic lead has lately been tried 
with promising results. Driers are generally incorporated with the 
oil by aid of heat. However, interesting attempts have been made, 
to effect this result in the cold. 



Treatment op Linseed Oiii with Driers in the Gold. 

Numerous attempts have been made to prepare quick-drying oils 
without the intervention of heat, the great inducement being economy 
and a paler oil. Few processes have, however, been published. The 
simplest plan consists in passing the oil into a reservoir, from whence 
it falls upon plates superimposed at alternating inclinations and at 
certain distances one from another. The oil thus runs in a thin 
layer in a zigzag course &om one plate to another and thickens as it 
absorbs oxygen ; by using lead plates the action is more rapid. The 
oil when it reaches the bottom of the colunm of plates is pumped up 
to the top, and the same process is gone through again, and so on 
until the oil has assumed the requisite consistency. The theory of 
this is very simple, the oil oxidises, generates fatty acids which attack 
the lead and the resulting nascent Hnoleate of lead dissolves in the oil. 

1. Sink's Method, — In Bink's process a very small quantity of 
drier (2 to 6 parts in the thousand), consisting of a mixture of oxide of 
manganese and a salt of lead is first added to the oil, then a current 
of air is passed through the mass until the desired quantity of oxygen 
is absorbed. But this process does not give satisfactory results with- 
out the aid of a moderate heat. 

2. Bouts* Process. — Bonis proposed to introduce oleate of lead 
into the oil ; the product is colourless and dries well enough. It has. 
been proposed later to replace the oleate by the linoleate of lead, but 
the latter, it is said, does not give the same result as it is said to be 
insoluble in oil in the cold. Hartley and Blenkinsop dissolve the* 
linoleate of manganese in naphtha and introduce it in solution in that. 
vehicle into the oil and then blow air through it. But according to> 
Professor Sabin, this process was well known in America long before 
Hartley, etc., patented it. Moreover the writer recommended it in 
his Polytechnic lectures several years before. See Vincent's method . 
of oil boiling, p. 49. 



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OIL BOILING — THEORETICAL AND PRACTICAL. 33 

3. Liebig's Method. — Liebig recommended the agitation of the 
oil with water, litharge and basic acetate of lead. The latter salt is 
prepared by grinding as finely as possible 1 part of acetate of lead 
^th 1 part of litharge to thorough incorporation, and placing the 
mixture in a porcelain basin, which is heated on the water bath and 
covered with another porcelain basin to prevent access of air. After 
an hour's heating a white mass is obtained, which is triturated with 
6 parts of water. The solution on standing and clarifying contains 
the basic acetate of lead. It is diluted with its own bulk of water, 
and vigorously shaken with 20 parts of oil which has been triturated 
with 1 part of finely ground htharge. The mixture thus obtained is 
added to the oil to be treated, which it soon decolorises, and at the 
same time stimulates its drying properties. In those cases where 
the presence of lead would be prejudicial to the object for which the 
oil is to be used, it is agitated with a small quantity of sulphuric 
acid diluted with 3 parts water. The lead may also be eliminated by 
agitating the oil with a salt of manganese, the acid of which forms 
an insoluble lead salt — the sulphate, for example, or, better, the 
borate.^ 

4. Livache's Process. — Livache's process consists in agitating the 
oil in the cold with finely divided metallic lead, perfectly free from 
oxide. For this purpose he uses the spongy lead obtained by pre- 
cipitating a lead solution by zinc plates. For 1,000 gallons of oil, 
30 lb. nitrate of lead are dissolved in 15 gallons of water; about 
1 ounce of nitric acid is added, then 6 lb. of sheet zinc. The pre- 
cipitated lead is placed in capacious funnels plugged with shavings,. 
or, better stiU, with sea- weed, where it is rapidly washed with water ; 
then a small quantity of oil is poured on very gently, so as to displace-, 
the water imbibed by the porous mass of precipitated spongy lead.. 
When the oil runs away clear and limpid from the bottom of tha: 
funnel, and as a consequence thereof all the water has been displaced^ 
the mud thus obtained is run into the tank containing the 1,006' 
gallons of oil, where the whole is subjected to agitation. In working; 
with small quantities the requisite agitation may be imparted by 
running the oil and lead into a cask, and rolling it about from time 
to time on the floor. The oil thus treated assumes a reddish tint„ 
which disappears as soon as it oxidises in contact with air^ If the 
treatment has been efficient, the resulting oil is as fluid as the 
original, contains a small quantity of lead, and dries in twenty-four 
hours in the open air. The rationale of this process is easily seen, 
the fcbtty acids originally present on the oil act on the finally divided 
metalHc lead, and the nascent Hnoleate of lead, aided by the heat 
produced by its formation, dissolves in the oil as soon as formed. It 
is advisable to introduce manganese into the oil prepared in this way. 
A salt of manganese very soluble in oil, viz., the nitrate, is added, 

* Liebig's method is regarded by some as simply a method of refining the oil. 
It was all Liebig claimed for it. — J. G. M. 



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34 MANUFACTURE OF VARNISHES. 

say, 15 lb. for the proportions given, and the whole frequently 
stirred for two or three days, after which it is allowed to stand and 
decanted. If this oil were at once used, as it often contains an excess 
of nitrate of manganese, which deliquesces in the air, it might dry 
dull. To obviate this, 7^ lb. of dry precipitated oxide of lead are 
added, and the whole again subjected to agitation. After standing a 
perfectly clear oil is obtained, which, exposed to the open air in a 
thin layer, at the ordinary temperature dries in six hours. During 
drying the absorption of oxygen produces, in consequence of the 
presence of oxide of manganese, a brown coloration, but the latter 
soon disappears, and finally a beautifully brilliant, perfectly dry and 
completely colourless coat is obtained. Some manufacturers using 
this process have found the oil in certain cases to be tacky, perhaps 
owing to the presence of a small quantity of glycerine. This has led 
them to heat the oil treated first with finely divided lead and then 
with a salt of manganese, and it would appear that they have 
obtained very interesting results. (See pp. 126-127.) 

Lewkowitsch, in a recent lecture, has revived the idea that linseed 
oil can be converted into what is to all intents and purposes a boiled 
oil by grinding it in the cold with borate of manganese. This would 
have, in the absence of free fatty acid and free hydrated oxide of 
manganese, no more effect on linseed oil than grinding it with so 
much pumice-stone. The writer proved this in an unpublished 
experiment made some fifteen years ago. He triturated linseed oil 
with borate of manganese both in the cold and at 100° C. for nearly 
A week, and the oil scarcely dried any better than raw oil. The 
spreading of such erroneous doctrine is to be deprecated, notwith- 
standing that the great Chevreul stands sponsor for it. There is no 
getting over the fact that the drier must first of all be dissolved in 
the oil before it can act. 

Boiling Oil Throttgh the Bung-Hole. — The American process of 
making "boiled" oil in the cold, or, as they term it over there, 
boiling oil through the bung-hole, consists in simply dissolving fused 
linoleate of lead or manganese, or their rosinates, in spirits of tur- 
pentine or naphtha, and adding a certain amount of this solution to 
each barrel of raw oil. The painter does the same thing when he 
adds " terebine " to his paint. 

Employment of Boiled Oil in Painting, 

Boiled oil or oil prepared as just indicated is a very important 
factor in painting. In fact, in house decoration raw linseed oil is the 
vehicle used in painting. It is ground along with white, that is to 
say, white lead, so as to obtain a soft paste, which is thinned down 
in various proportions with linseed oil and spirits of turpentine imtil 
the desired fluidity is obtained. If a certain shade is desired, the 
colouring matter beaten up with a small quantity of oil is added ; 
finally, if very rapid drying is required, what are biown as " Patent 



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OIL BOILING — THEORETICAL AND PRACTICAL. 35 

Driers " (siccatives) are added. These may consist of (1) a solid 
powder (litharge, red lead or zumatic, i.e., a mixture of oxide of zinc 
and borate of manganese) ; (2) litharge or manganese-boiled oil when 
there is no reason to fear the painting, or by a drying oil, the drying 
properties of which have been stimulated by appropriate treatment 
(precipitated lead, acetate of lead, etc.) ; or (3), finally, of special pre- 
parations, the base of which is oil known under the name of liquid 
driers, but which are only used with coloured pigments, as they turn 
white tints yellow. (See pp. 84-93.) 

The paint thus formed slowly changes when spread upon any 
surface in a thin layer to a solid body, which forms a protective coat- 
ing against external influences. 

The paint ought not to dry too quickly, for the slower it dries the 
more it is capable of expanding, and thus lasting the longer. 

The fluidity ought to be such that the paint flows easily from 
the brush whilst at the same time it does not run in streams, but 
forms a homogeneous coating. The coating must also be thin enough 
to prevent the formation of pellicles at the surface, which would 
hinder the part underneath from drying. It is therefore advisable to 
apply several successive coats. But each of these ought to be allowed 
to dry thoroughly before the succeeding one is applied. With linseed 
oil substitutes, none of which can possibly form insoluble Hnoxin on 
drying, the second coat of paint is sure to disturb the first, especially 
if applied to outdoor work in warm weather, and if spirits of turpentine 
or thinners be added to hasten the drying. Substitutes of all kinds 
should be avoided. They give rise to more worry and annoyance 
than eventual economy. In some extreme instances one might as well 
apply methylated spirit to wood coated with, brown hard spirit var- 
nish as apply a second coating of these substitutes. 

In using boiled oil a brilliant coating is not aimed at, the question 
of appearance being subordinate to that of resistance and durability. 
It is preferable to impart brilliancy by a final coat of varnish. 

For the grinding of paints in oil, stiff and liquid, see J. Gruick- 
shank Smith's Manufacture of Paint (Scott, Greenwood & Co.). 

Oil Boiling. 

Oil is generally boiled in cast-iron pans, best made in the form of 
an inverted truncated cone, so that in frothing up or priming the oil 
may spread over a larger surface. Becently oil-boiHng pans have 
been made of enamelled iron, especially on the continent, but their 
use is for obvious reasons far from general in this country. In 
general the pan is half filled with oil and heated for three hours. For 
some purposes the oil is set on fire a few minutes before the fire is 
drawn. At other times the oil is heated to a much higher tempera- 
ture, viz,, 200** to 226° C. (392° to 437° F.), and this temperature is 
maintained, says Livache, in some cases as long as eight days, a 
seemingly irrational time. So that the heat may not accidentally 

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36 MANUFACTURE OF VARNISHES. 

rise too high a small quantity of tin is added to the oil, and care 
taken that the heat does not reach its melting-point, 228° C. (442*4'' 
F.). Should a viscous or a good bodied oil be required, the tempera- 
ture is raised to 316° C, say, 600° F., and kept thereat from six to 
eight hours. But with oils to be used in the preparation of pale 
varnishes, it is not desirable to heat the oil to too high a temperature, 
which would impart to it a brown colour and start the destructive 
distillation of the oil, liberating a certain proportion of linoleic acid, 
which dries more slowly than hnolein. To produce a superior article 
the heat should not be raised so far as to start destructive distillation 
or " crack " the oil, which should rather be kept at a temperature 
which would bring about polymerisation, an object attained by slow 
boihng at a temperature regulated between 160° and 200° C. (302° to 
392° F.). The lower the temperature at which the oil is kept the 
longer does the process last. According to Livache this is the 
method adopted in England, where the oil, he says, is boiled for a 
very long time, often extending over a week; but by working in 
that way a very pale oil is obtained, presenting great elasticity and 
possessing properties which more than compensate for the length 
of time occupied in the process. But as a matter of fact, the 
bulk of the boiled oil made in Britain is made by some modification 
of Vincent's process (p. 49), and does not last more than thirty-six 
to forty-eight hours at the most. The point is to get the small 
amount of manganese into the oil. The air afterwards does the rest. 

Treating Oil with Driers, — It has been seen that those which 
have really a beneficial influence upon the drying of oils are lead and 
manganese either in the state of metals, oxides or salts. In actual 
practice the oxides of lead and manganese or their salts are preferred ; 
nevertheless the use of metallic lead has lately been tried with 
promising results. (See p. 33.) 

Driers are generally incorporated with the oil by aid of heat. 
However, interesting attempts have been made to effect this result 
in the cold. (See p. 32.) 

In 1891 F. H. Thorpe tried to determine the influence of tem- 
perature and of the various driers on linseed oil during boiling. 

Calcutta raw linseed oil was employed. It had a very pale 
yellow colour, and had been cold pressed. In each experiment 60 c.c. 
of oil was used. This was put into a tube of thin Bohemian glass, 
which was plunged with several others into a sand bath, the sand 
reaching half-way up the contents of the tube. During boiling the 
contents of the tubes were stirred. The drier, before being intro- 
duced into the oil, was dried. The best results were got by heating 
the sand bath up to between 230° and 276° C. After heating the 
quality of the oil was gauged by covering small plates of glass with 
it and allowing it to dry in a ventilated room. The varnish was con- 
sidered dry when it could be touched without leaving finger-marks 
upon it. The following table gives the results obtained. Some of 
them do not seem altogether in accordance with results obtained on 



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OIL BOILING — THEORETICAL AND PRACTICAL. 



37 



the large soale. But results obtained by heating tubes in sand can 
hardly be regarded as comparative. 

Again, the influence of mass in oil boiling makes itself felt as in 
other chemical operations. Mere laboratory experiments can only 
serve as a rough guide. 





13 


L 


a 


& 




Siccative. 




11 


if 

II 


S-s- 


Appearance of the 
Dry Coat. 




cStr- 


fl 


s 


g 









^ 


S 


S 




Litharge _ _ . 

»» . - - - 


1-0 
0-2 


2J 
2J 


220 
250 


6 
10 


Almost colourless. 
11 11 


»» - - - 


0-8 


IJ 


260 


10 


11 11 


Peroxide of Lead - 


1-072 


l| 


220 


several 
days 


Strongly coloured. 


Chloride „ 


1-274 


2^ 


260-360 


24 


Slightly „ 


Red Lead 


1-024 


2i 


220-286 


24 


Strongly „ 


Oxalate of Lead - 


1-323 


2i 


300 


did not 
dry 
24 


»» »i 


Tartrate „ 


1-6 


H 


270 


11 11 


Acetate „ 


1-46 


^i 


270 


12 


Slightly „ 


Borate „ - - 


1-106 


H 


220-300 


20 


11 11 


Carbonate „ 


1-197 


2 


226 


10 


11 V 


Oxide of Zinc 


0-5 


2J 


260 


45 


Almost colourless. 


Sulphate „ 


1-987 


2J 


286 


46 


11 1} 


»i 11 


1-6 


2 


230 


45 


Yellow. 


Acetate „ 


1-0 


2i 


235-280 


40 


Colourless. 


Borate 


1-0 


2 


240 


40 


Almost colourless. 


»» »» ~ " 


0-6 


li 


240 


46 


11 11 


>» 11 ~ " 


0-6 


li 


240 


46 


11 11 


Citrate 


1-6 


2J 


230 


36 


11 11 


Acetate of Manganese - 


1-0 


2z 


225-260 


20 


11 11 


Borate 


1-626 


H 


220 


20 


Colourless and hard. 


Sulphate ,, 


1-72 


2 


240 


40 


Colourless. 


Oxalate 


1-64 


2 


230 


40 


11 


Acetate „ 


0-6 


2 


225-260 


20 


Strongly coloured. 


Borate „ 


0-6 


1 


230 


20 


Colourless. 


Acetate 


0-6 


li 


225-260 


20 


,^ 


Oxalate 


1-6 


^ 


230 


36 


jj 


Sulphate 


1-6 


^ 


240 


36 


11 


Oxalate „ 


1-0 


^ 


240 


48 


YeUow. 


Citrate 


1-6 


H 


230 


24 


Black. 


Tartrate 


1-0 


2i 


230 


24 


Colourless. 


Formiate „ 


1-0 


1 


200 


24 


Slightly coloured. 



The figures in the following table give the amount of metal, 
whether lead or manganese, in certain well-known driers, the number 
of pounds per ton of oil to use, and the temperature at which they should 
be incorporated. The temperature at which the drier dissolves should 
never be exceeded except with the view of hastening the process in a 
rational manner (Weger). 



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MANUFACTUBE OF VARNISHES. 



Drier. 



Percentage 

of metal in 

commercial 

product 



ton of oil. 



Lb. per Temperature, 



Degrees C. 



Manganese Peroxide, MnO^ .... 

Hydrated Manganic Oxide, Mn20,H30 
Hydrated Manganese Peroxide, MnOaH^O - 



Litharge, PbO 



Manganese Borate ... 
Manganese Borate Commercial - 

Precipitated Manganous Bosinate 
Fused Manganic Bosinate - 
Linoleate of Manganese 

Lead Manganese Bosinate . 



30-60 Mn. 

46-60 „ 
46-60 „ 



93 Pb. 



16-20 Mn. 
6Mn. 

7 

4 

10 
8-10 Pb. 
1-2 Mn. 




260 
180-200 
better 
200-220 

160 

generally 

higher. 

In the cold 

generally 

200 and 

higher. 

In the cold 

generally 

130-160 



Oil Boiling by Naked Fire. — When only small quantities of 
boiled oil are required, the most simple plan is to boil the oil in an 
iron or copper pan of about 20 gallons capacity, with an enlarged 
mouth to prevent the oil from frothing and threatening to prime over. 
This pan is at a certain height furnished with a collar or circular 
flange which supports it on the rim of a sheet-iron furnace, fed pre- 
ferably with wood charcoal. The pot being filled to the extent of 
half of its capacity with oil, and therefore containing about 10 or 11 
gallons, the fire is lighted, and as soon as boihng commences the 
driers are added in small quantities at a time with constant stirring 
with an iron rod. The proportion and the nature of the driers used 
vary much, according to And^s ; for the quantity of oil in the pot, 
either of the following mixtures may be used : — 

2^ lb. of red lead and 2^ lb. litharge ; or 
2^ lb. of lithsbTge and 2^ lb. sugar of lead ; or 
l| lb. of red lead and 3| lb. sugar of lead ; or 
1^ lb. to Sf lb. of borate of manganese ; or 
2^ lb. of hydrated oxide of manganese. 

The driers are previously ground as finely as possible, and the oil 
well stirred after each addition. As soon as the driers are all in and 
the frothing has ceased the pot is filled with oil just up to the neck, 
and the fire regulated so that the temperature does not rise above 
220° C. by means of a thermometer with metallic framework. The 
operation is generally complete in three hours, during which time the 
driers are frequently stirred up from the bottom. The pot is then 
withdrawn from the fire, and the oil is set aside to clarify ; or if it be 
desired to start boiling a fresh batch it is run into a galvanised 
wrought-iron tank. 

Though this is a very simple arrangement, it has the great draw- 
back that the pot full of hot oil has to be Hfted down from the top of 



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OIL BOILING — THEORETICAL AND PRACTICAL. 



39 



the furnace, thus greatly enhancing the risk of accidents. Further, 
when several consecutive boilings have to be made the heat is badly 
utilised. To remedy these inconvenient defects a furnace built in a 
framework of masonry is used. This furnace is sometimes covered 
with an iron plate, with a circular hole into which the pot fits. 

More often, however, the fire is imderground, thus enabling the 
workman to watch the operation at his ease, since the pot is then on 
the same level as the ground. 




Fig. 11. — Portable Oil-boiling Pot. A, B, flue and chimney-stalk; C, plate on 
which flange of pot rests. 



A rather different kind of pot (Fig. 11) is used, and so constructed 
that the oil does not receive throughout its whole mass and at the 
outset the heat stored up in the brickwork. To obviate this the 
pan of about 20 to 22 gallons capacity, generally of cast-iron, 
enamelled inside, is contracted in the middle, and rounded at the 
base, so that the bottom only is exposed to the action of the heat. 
Otherwise the process is conducted in the same way as before, only 
the oil is heated a little longer, say, four hours instead of three. 
This pot is lifted off the fire on to an iron stand (Fig. 12) by two 
wrought-iron bars, 7 to 10 feet long, passing through loops fixed 



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40 



MANUFACTUBE OF VARNISHES. 



to the side of the pot, so that in case of fire the bearers may be at a 
safe distance. 

When large quantities of oil are to be boiled no good purpose is 
served by multiplying operations. It is better to use larger pans. 
In an extensive business the pans may measure 6 feet 6 inches high 
by 6 feet in diameter. Nevertheless we more often meet with pans 
having a capacity of 60 to 120 gallons. The pan is of strong iron 
plate about J of an inch thick, is built into masonry in such a manner 
that the upper part controls a circular gutter of 1^ to 2 inches deep, 
which, in case of the oil boihng over, conducts it to an adjacent re- 
ceiver. The pan can be so built into the brickwork that it may be 
heated on a part of its bottom and its sides, or, on the contrary, and 
preferably, on its sides alone. In the first case it so rests on the 
brickwork that the centre part of the bottom is exposed ; in the second 
case, so as not to overheat the bottom part, it is supported by a small 
arch of brickwork, thus preventing solid matters from tenaciously 
adhering to the bottom. The cylindrical form of pan is not always 




Fig. 12. — Iron Stand (double) for holding Pot shown in Fig. 11, after Bemoval 

from Fire. 



adopted. We often come across pans almost conical in shape, the 
narrow part of which forms the bottom — a form which has the ad- 
vantage of distributing the heat more evenly, and, owing to the larger 
section, of diminishing, in case of frothing, the chances of the oil 
running over. Such a pan is half or at the most two-thirds filled 
with oil and at first heated gently, and when the oil reaches 100° C. 
(212° F.) the impurities on the surface are skimmed off. The driers, 
previously completely desiccated and ground very finely, are then 
added. It would not do to add them in the beginning, as they 
would fall to the bottom, and their effect be to a great extent lost. 
And^s gives the following proportion for 20 gallons of oil : — 

"2^ lb. red lead, 2| lb. litharge ; or 
21 lb. litharge, 2| lb. sugar of lead ; or 
1| lb. borate of manganese ; or 
2^ lb. hydrate of manganese. 

Boiling is kept up for five hours at a temperature not exceeding 
220° C. (396° F.). The temperature is regulated by means of a ther- 
mometer in metal framework, or, better still, by an aneroid thermo- 



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OIL BOILING THEOEETICAL AND PRACTICAL. 



41 



meter, which is more legible, and not so fragile. Sometimes the 
heat may be regulated by adding some tin, and taking care that the 
heat does not rise to the melting-point of the latter, viz., 228"* C. 
{442*4'* F.). The degree of heat was at one time ascertained by dip- 
ping the qnill end of a feather, which ought to at once shrivel and 
curl up, into the oil. This is still a handy test although the ultra 
scientific may sneer at it. The more attention there is paid to ensure 
a. constant regulated temperature, the brighter and paler will be the oil. 
When very quick drying properties are aimed at the oil is boiled 
from one to two hours longer, and the amount of driers increased 




:>FiG. 13. — Plant ,for;Oil [Boiling by Naked Fire {with Rctnovahle Grate Running 

on Rails], 



from 20 to 25 per cent. Ajb the time of adding the driers the oil 
should be well stirred either with an iron spatula, or preferably by 
means of mechanical agitators (a revolving shaft with arms, or a 
simple hanging chain fixed at both ends to a horizontal shaft, bent 
twice at right angles, fixed above the pan ; the chain descends almost 
to the bottom of the pan and is turned by means of a crank some 
distance away). 

A wood charcoal fire allows a constant temperature to be main- 
tained if the fire be well regulated. Coke will suit equally well. So 
as to lessen the risk of the temperature rising too suddenly, which 
would colour the oil and cause it to overflow or aggravate the risk of 



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42 



MANUFACTURE OF VARNISHES. 



fire, it has been suggested to use a movable grate, which can be 
lowered instantaneously, and thus cause the fuel to fall into a pit full 
of water (see Fig. 15). Movable car furnaces running upon rails (Fig. 
14), and thus capable of being easily removed, have also been employed. 
Oil is sometimes boiled by immersing the pan in a sand bath, or in a 
bath of a suitable alloy. But this plan is hardly to be recommended, 
because if the temperature rises too high, the oil cannot be withdrawn 
from the source of heat; the same thing sometimes happens when 
the pan is built into masonry or set in brickwork, for even in the case 
of a movable furnace the oil remains exposed to the action of the heat 
stored up in the brickwork. 

To remedy this the pan, which sometimes measures more than 
9 cubic feet, is mounted on a kind of trolley. The circular opening 
of the fire is level with the ground. If the temperature rises too 
high the trolley supporting the pan is removed from the fire; a 




Fig. 14. — Movable Furnace and Oil-boiling Pan. 



movable hood with counterpoise descends over the top of the pan 
and carries away the fumes. This enables the oil-boiler or varnish- 
maker to watch the operation very easily, and preserves the metal 
of the pan. When the operation is terminated the oil is ladled out, 
and on the large scale pumped, into a galvanised iron tank. As soon 
as the pan is empty it is immediately recharged with another batch, 
and generally without being cleaned in any way. The coating which 
forms on the sides of the pan prevents the oil from darkening, but 
care must be taken to remove any excess of driers from the bottom 
of the pan, otherwise unintentionally an excess of driers, which might 
have an injurious effect, may be added to the next batch. When the 
skin becomes too thick it is scraped off. In certain factories this ia 
only done once a year, or once in two years. The foots from oil 
boiling by fire may be used in making black paints, which are so 
difi&cult to dry. 



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OIL BOILING — THEORETICAL AND PRACTICAL. 



43 



Fire Bisks and Prevention of Nuisance. — During boiling, pungent, 
very inflammable, vapours are emitted. Working with small quan- 
tities of oil all that is generally deemed necessary to prevent fire is to 
have a cover at hand to place on the pot should the oil take fire. On 
the large scale, when the oil is heated in a pan, a hinged lid is fixed 
over the pan during the boiling by means of a cord. If the oil takes fire 
the cord bums, and the cover falls automatically on to the pan. Dif> 
ferent arrangements have been adopted so as to mitigate the fumes. 
On the small scale, a simple hood connecting with a chimney-stalk of 
sufficient elevation and cbaught is placed above the pot. A better 
plan is to fix a sheet-iron cap above the pot (Fig. 15), provided with 




Fig. 16. — K, Oil-boiJing pan, with fire-quenching arrangement ; R, agitator with 
blades ; M, crank-handle working cog-wheel gearing, ; H, hood to convey 
fumes to chimney-stalk, E ; R, hearth, the bars of which are kept in posi- 
tion by the rod S, by means of which, if the oil threatens to prime over or 
catch fire, the furnace may be extinguished by tilting its contents ^into the 
vessel W, filled with water. 



an opening in front by which the process may be watched, or the 
contents of the pot stirred. This cap is connected by means of a 
pipe with a tall chimney shaft, the lower part of which is closed by 
a plug. Here thick viscous products with a vile odour condense. 
They are removed from time to time by opening the plug. The more 
volatile products escape from the top of the chimney. But it is 
better not to let the fumes escape directly into the air, but to pass 
them through a condenser in connection with the chimney. A very 
simple way is to cover the boiling pot with a movable lid, with a 
window in the centre capable of being opened so as to allow of 
stirring the oil. On the side is a disengagement tube, which can be 



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44 MANUFACTUEE OF VARNISHES. 

luted to a pipe connected with a condenser. The latter may be a 
pipe, shaped like an organ pipe, leading into a vessel containing water, 
or it may consist of a vertical cylinder, the interior of which contains 
a coil of piping, through which cold water circulates. The vapour 
passes through the space not occupied by the pipes, and is in a great 
measure condensed. The advantage of this is that the wide, straight 
cylinder is not so liable to get choked up. It is advisable to use an 
aspirator because the vapours are very heavy, but working with one 
or other of these arrangements condensation is almost complete. If 
need be the uncondensable vapours may be led through a fire to bum 
them, as shown in Fig. 16 (p. 47). Often no previous condensation 
is attempted, and the fumes are led directly into the fire. At first it 
was supposed that explosions would occur, but the large quantity of 
air which is mixed with the fumes does away with any danger. It 
is, however, necessary to be very careful that the oil in the pan does 
not catch fire when these products are conveyed directly to the fire 
which heats the pan, or to a special furnace. The oil may take fire 
by the heavy vapours condensing in the pipe almost as soon as they 
leave the pan, and should there be any flaw they may run slowly 
backwards towards the fire and there become inflamed, and thus 
heat to redness the connecting pipe, which is generally of sheet iron, 
and thereby set fire to the condensed products in proximity to the 
boiling oil, and thus to the oil itself. This is easily remedied by pro- 
tecting the lower part of the conduit pipe by fire-clay bricks, and 
adding a damper, so that communication may be shut off should the 
temperature rise too high. If the fumes be condensed by means of 
a properly constructed condenser between the pan and the fire, no 
fear need be entertained. 

Choice of Drier — Manganese Driers. — ^It has been shown that the 
best results are obtained by the use of lead and manganese. In 
particular, an oil boiled in contact with manganese dries quicker 
than one boiled with lead. When boiled oil is free from lead it has 
the advantage of not being altered by sulphur compounds. The 
receipts given for the different driers to be added recommend the 
use of the borate and the hydrated oxide of manganese to the exclu- 
sion of all lead compounds, and the boiling may be done as suggested. 
The superiority of oils having manganese as their only drier is so 
decisive that attempts have been made to manufacture such oils 
directly. 

1. Borate of Manganese. — Two pounds of very white borate of man- 
ganese, free from iron and finely ground, are added with constant 
stirring to 1 gallon of oil heated to 100° C. (212° F.). When complete 
incorporation is effected the heat is raised to 200° C. (392° F.). One 
hundred gallons of oil are heated in a pan until bubbles of gas com- 
mence to come off, when the preceding mixture is added in a thin 
stream. The heat is raised to about 200° to 220° C. (392° to 428° F.), 
and after twenty minutes' boiling an oil is obtained which rapidly 
dries to a bright elastic coat. It is absolutely necessary only to use 



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OIL BOILING THEORETICAL AND PRACTICAL. 45 

borate 'of manganese completely free from iron. It is prepared, 
according to Livache, by adding a solution of borax to a solution of 
chloride of manganese, so long as a precipitate is formed which is 
washed with water and dried. A perceptibly white product is thus 
obtained. 

As manganese ores are Hable to contain iron, lime and other im- 
purities, this method of preparing borate of manganese is apt to give 
an impure product ; a better method is that given on pp. 89-90. The 
drying properties of this salt are such that it is claimed by some that 
it can transform linseed oil into a quick-drying oil at a temperature 
as low as 40° C. (104° F.), e.g.^ if in a flask containing Unseed oil we 
suspend a small linen bag containing borate of manganese (3 oz. of 
borate to 100 oz. of oil), and if we place the flask in a warm place we 
obtain in fifteen days a quick-drying oil. But all these trivial pro- 
cesses are misleading. Life is too short to wait fifteen days for oU to 
dry no quicker than boiled oil, and only under exceptional conditions, 
such as the presence of free fatty acid in the oil and free hydrated 
oxide of manganese in the borate, can the oil be acted on at such 
low temperatures. Common-sense might tell those who make such 
extravagant claims for borate of manganese that in the cold it is as 
inert as ground pumice-stone or sand. (See also p. 34.) 

Yet we obtain a better oil if, instead of employing borate of 
manganese alone, we employ a mixture of borate of manganese and 
oxide of lead, which is practically the same, because the reaction 
which ensues introduces oxide of manganese, but the latter may be 
added directly in the form of the hydrated oxide — a dense, brown 
product ; finally it can be introduced by utilising reactions similar to 
the following : — 

2. Hydrated Oxide of Manganese and Air, — One thousand pounds 
of oil are heated to 70° to 80° C. (158° to 176° F.) ; on the other hand, 
3 lb. of crystallised sulphate of manganese are dissolved in a very 
small quantity of water by the aid of heat ; 10 lb. of caustic potash 
dissolved in a small quantity of water are added ; the whole well 
stirred and run into the oil. The mass turns brown, and brightens 
at the same time. An india-rubber tube, to the end of which a rose 
nozzle is fixed, is introduced into the pan, and by means of a pump 
air is injected for four or five hours until the brown coloration has 
disappeared. 

It has Hkewise been proposed to cause the oil to which the above 
mixture has been added to fall in drops inside a pipe, where a 
current of air circulates the reverse way. The oil is again elevated, 
and made to fall again, and so on until the brown coloration dis- 
appears. (Fig. 22, p. 58 and context.) It has been further pro- 
posed to use the natural black oxide of manganese — pyrolusite. 

3. Black Oxide of Manganese and Sulphuric Acid. — A mixture of 
2 lb. of finely groimd pyrolusite and 2^ lb. of sulphuric acid is added 
to 100 lb. of Unseed oil heated between 180° and 200° C. (356° to 
392° F.), After about an hour, a milk of lime, obtained by slaking 



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46 MANUFACTURE OF VARNISHES. 

1 lb. of quicklime, is added, the whole well stirred, and filtered 
through canvas. 

4. Varioris Processes. — (a) Livache claims that a very quick-dr3dng 
oil — ^free from lead — whose drier is manganese may be obtained in 
a roundabout way by slightly heating or simply agitating an oil 
which has been boiled with litharge, with borate or sulphate of man- 
ganese. The oxide of manganese, he says, replaces the oxide of 
lead, which is precipitated in the state of insoluble borate or sulphate. 

(b) One hundred gallons of linseed oil, for example, are heated with 
50 lb. of oleate of lead. It has been proposed to replace the oleate of 
lead by the linoleate, or more recently by the rosinate of manganese, 
which are used in smaller proportion. 

Zinc Driers. — The oil is sometimes boiled after the addition of 
white lead, acetate of lead and sulphate of zinc. The function of zinc 
sulphate in oil-boiling and varnish-making is obscure ; it is generally 
added with the idea of imparting elasticity. Again, attempts have 
been made to substitute lead salts by pure oxide of zinc, but, after 
boiling, the resultant oil dries slowly, and has no advantage over a 
litharge-boiled oil except that it is not blackened by sulphuretted 
hydrogen. It is much more profitable, says Livache, to precipitate 
the lead of a litharge-boiled oil by means of a suitable manganese 
salt such as the sulphate, but this is a very roundabout way of intro- 
ducing manganese into the oil. 

In certain cases it has been recommended to add oxide of zinc to 
the salts of manganese employed in oil boiling, but if the oxide of 
zinc did any good in these cases it was due to the liberation of oxide 
of manganese. Leaving out of account the advantage — often very 
appreciable — of obtaining an oil which does not blacken in contact 
with sulphuretted hydrogen, it would appear that the oil does not 
dry quite so quickly, nor so uniformly and well, as when a Salt of 
manganese is added in presence of oxide of lead. 

It has been recommended not to heat the oil with driers beyond 
120°'to 127'' C. (248° to 260-6° R), but to project into the oil after 
several hours' boiling :j-J^th of its weight of water, mixed with Jj^th 
of its weight of litharge, in the form of fine drops. But this process, 
due to Bartky and tried in Germany, appears to be but little used. 

Oil Boiling by Steam, — There are two great drawbacks to boiling 
oil over a naked fire, viz., the danger of fire and the dark tint which 
the oil assumes in contact with overheated surfaces. It has been 
tried to vemedy these by boiling oil by means of a steam heat, and 
this method of oil boiling ensures perfect safety, economy and 
rapidity, advantages which are the more to be appreciated because 
this method produces pale oils. The simplest plan is to heat the oil 
in a pan by means of a steam coil. Steam at about 4 to 5 atmo- 
spheres (60 to 75 lb. pressure) is passed through the coil so as to heat 
the oil to about 150° C. (302° F.), but a much lower temperature is 
sufficient, say, about 40 lb. steam. A mechanical agitator spreads 
the heat uniformly through the bulk of the oil. Working with a 



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OIL BOILING — THEOEETICAL AND PRACTICAL. 



47 



pan capable of holding half a ton of oil, when the oil has been heated 
for half an hour the necessary quantities of driers are added, and 
the boiling continued for six hours, the mechanical agitator being 
kept at work all the time. The process is, says Livache, rendered 
more economical by using superheated steam. In this case the 
steam before entering the pan passes through a coil in a furnace 
capable of bringing it to 400° C. (752° F.). When the superheated 
steam in its passage through the coil in the pan has brought the 
oil to the desired temperature, it is then only necessary to maintain 
it at that temperature by means of the steam admission valve. But 
there is no necessity for this superheating, 40 lb. steam does all that 
is .required. It is not intended to distil the oil, and unless this were 
80 there is no reason for superheating. 

To work as economically as possible, the gases evolved from the 
furnace in which the steam was superheated are led underneath the 




Fig. 16. — Fireproof Oil Boiling by Superheated Steam and 
Fume Consuming Plant. 

pan and burnt so as to assist in heating the oil. But if this arrange- 
ment be economical, it introduces the element of danger from fire, 
the obviating of which we had, amongst other advantages, in view 
when adopting the process of oil boihng by steam. In boihng oil by 
a steam coil there is always the serious drawback that there is a 
great difficulty in maintaining a uniform temperature throughout the 
mass even with continuous agitation. Effectual commingling of the 
oil and driers is not practicable ; the latter settle to the bottom, and 
the coil of piping prevents the agitator from reaching them. Were 
it not for this drawback linseed oil could be very well boiled in a com- 
paratively shallow, lead-hned, rectangular wooden tank lined with 
6 or 7 lb. lead. This drawback, however, could be easily got over by 
pumping in air through a perforated pipe laid down so that each coil 
thereof alternated with a coil of the closed steam pipe. This, in con- 
junction with the mechanical agitator, would effectually prevent the 



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48 



MANUFACTURE OF VARNISHES. 



drier from settling at the bottom. By suitable mechanical arrange- 
ments a boiling pan made in this way would be equally effectual and 
cost less, not only originally but also for maintenance, than the costly 
wrought- iron or copper vessel now in vogue. But certain manufac- 
turers deprecate the continuous stirring of the oil as likely to produce 
bad results. 

And^s obtained good results by using a steam-jacketed pan 
(Fig. 17), 85 gallons capacity, made from strong iron plate, ^ inch in 
thickness, and able to stand a pressure of 4 or 5 atmospheres ; it is 
provided with a safety valve, blow-off cock, and a tap to run off^ 
condensed water. About 40 gallons of oil are run into the pan, the 
steam turned on, and when the pressure is sufficient the blow-off cock 




Fig. 17.— Steain-Jacketed Pan for Oil Boiling. 



is opened for a minute to allow the steam and air to escape ; this is; 
repeated several times, and the escape valve adjusted, so that only the 
small quantity of spent steam, the replacement of which by super- 
heated steam is necessary to keep the pan and contents at the desired 
temperature, is allowed to escape. The condensed water is run off 
when necessary. The steam is regulated so as to keep the temperature 
between 125° and 132° C. (257° and 269*6° F.), and the process lasts, 
from five to six hours, but by prolonging the boiling and using more 
driers better quality oil is obtained. If care be taken not to exceed 
132° C. (269-6° F.) the resultant oil is very pale and bright. To 
stimulate oxidation during the boiling process, Andes fixes a mechanicaf 
agitator (E, Fig. 19) on the surface of the oil, which is propelled very 



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OIL-BOILING— THEOEETICAL AND PRACTICAL. 



49 



slowly. The same driers may be used as in boiling oil by fire, but it 
is advantageous to alter the proportions. Only half of the quantities 
of lead compounds shbuld be used, but double the quantities when 
working exclusively with hydrated. oxide of manganese or manganese 
salts. To economise, two steam pans may be wrought together, the 
steam passing from the steam-jacket of the one to that of the other 
(Fig. 19, I. and II.). But it is perhaps more advisable to utilise the 
waste steam (as shown in Fig. 16) so as to heat in an intermediate 
tank the next batch of oil as it comes from the settling tanks, and 




Steam-Jacketed Pan with Agitator for Oil Boiling, etc. 



previous to the actual boiling. This preliminary warming almost 
does away with the frothing of East Indian linseed oil, and the con- 
sequent liability of the oil to prime over into the condenser when it 
is heated in the jacketed pan in the usual way. 

Vincent* s Process for Oil Boiling by Steam with SimtdtaneoiLS In- 
jection of Air, — In Vincent's process a pan, preferably of copper, is 
used — having a depth equal to its diameter, of 2 to 10 tons capacity, 
and surrounded with a steam-jacket, E, up to three-quarters of its 
depth, or to the oil level or a little above it, and capable of withstanding 
a working pressure of 40 lb. to the square inch — into the interior of 

4 

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50 



MANUFACTUEE OF VARNISHES. 



which the steam is led, as a source of heat, and so regulated as to 
register throughout the process a pressure within the jacket of 35 
lb. to the square inch. The top of the pan is closed by a dome 
riveted to it, and pierced with a manhole. In the centre is a 
stuffing-box through which pass two concentric vertical shafts — a 
hollow shaft encircling a solid one — armed with blades. By means 
of exterior gearing (Fig. 20, B) these fans turn in opposite directions, 
and in so doing intersect each other, and thus by their ** dashing and 
cutting " action cause energetic agitation of the oil and thorough 
incorporation therewith of the driers. From the dome the fumes 
are either led by a 6-inch pipe to a condenser or into the furnace for 
heating the steam boiler. Finally, as soon as the pressure of steam 




Fig. 19.— Steam Oil-boiling Pans, showing how to connect up series from same 
steam supply pipes ; I., exterior view ; II., section; B, agitator; KK], steam 
jacket ; S, steam coil ; L, raw oil charging pipe ; F F, boiled oil discharging 
pipes ; D D, steam inlet pipes ; S A, condensed water and waste steam exits. 

on the pan registers 35 lb. to the square inch, equal to a temperature 
of 126*8° 0. (260° F.), air is injected under pressure by means of a 
pipe passing through the jacket into the bottom of the pan. 

The oil to be boiled at one operation is first pumped into a large 
reservoir (Fig. 16), where it is stored as long as possible ; from this 
reservoir it is run into an intermediate tank (Fig. 16) traversed by a 
IJ-inch coil of iron piping through which the waste steam from the 
pan passes, thereby economising expense besides facilitating the de- 
position of impurities. The oil thus heated to about 35° C. (95° F.) 
is pumped or run by gravitation (see Fig. 16) into the pan, and steam 
turned on in the jacket. As soon as the pressure marks 2 atmo- 
spheres, 35 lb. to the square inch, the agitators (Fig. 20) are put in 



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OIL-BOILING — THEORETICAL AND PRACTICAL. 



51 



motion and air pumped in. The finely pulverised drier, beaten up with 
a little oil to the consistency of treacle, is introduced into the pan 
slowly and in a thin sti'eam through a funnel with a stop-cock fixed 
in the dome as soon as the oil in the pan has become evenly and 
thoroughly heated through its bulk, or about half an hour after the 
steam indicates a pressure of 35 lb. Introducing the drier in this 
highly comminuted condition prevents coagulation, and thus gives 
practical effect by complete diffusion throughout the oil to Vincent's 
theory of oil boiling by steam, which requires each particle of oil to 
be in contact with, or in proximity to, a particle of the drier used and 
the oxygen of the air at the same time. Air is injected in this way 




Pig. 20.- 



- Jacketed Pan for Oil Boiling, with dome, A, fitted with agitator driven 
by cog-wheel gearing, B,'and pipe, C, leading to condenser. 



SO long as it is absorbed and does not cause the oil to froth up and 
prime over into the condenser. It was thought at first it might be 
advisable to heat the air before injecting it into the pan, but this 
would appear to be useless, as it becomes so heated by the pressure 
to which it is subjected in overcoming the weight of the oil, lifting 
the heavy valves, etc., that the pipes through which it passes cannot 
be held in a firm grip in the hand, and not only so, but its passage 
through the oil cools the latter but very little. The process lasts 
four hours. By means of a 2-inch pipe (D, Fig. 20) in the bottom of 
the pan the oil is run into tanks (Fig. 21) where it deposits any un- 
dissolved driers, etc. It is through this discharge pipe that the air is 
injected into the oil. Injecting it in any other way leads to the 



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52 MANUFACTURE OF VARNISHES. 

injection pipe getting choked up with oil-skins, etc. BoiUng oil by 
Vincent's process is especially apphcable for use with the rosinates 
and linoleates of manganese. Vincent left us no record of the drier 
he used, possibly it was the borate of manganese ; but the solution 
given under manganese acetate (p. 89) is an excellent drier for use 
in this process in the proportions stated. 

Boiling by Superheated Air. — Notwithstanding the advantages 
incidental to the process of oil boiling by steam, there is one draw- 
back which has been considered so serious by some manufacturers 
as to lead them to give up this method. They found that even with 
superheated and thoroughly dried steam there was always a certain 
amount of moisture which acted on the metal of the pan, piercing it 
in holes and causing bursting or explosions. Superheated air was 
therefore substituted for superheated steam. This air is drawn by 
means of a fan from the superheater to the (steam) coil or jacket, 
and is again returned to the superheater, thus working in a continuous 
cycle. The difference between the specific heat of steam and that 
of air renders the economy of the hot-air process very problematical. 
The coil in the pan is made of copper, which, although dearer than 
an iron one, has the advantage of not colouring the oil. As copper 
is also attacked by hot oil, it has been recommended to electro-plate 
it with silver. The coating need only be but very thin, as it under- 
goes no wear and tear* 

BulesfoTf and Changes which take Place in. Oil Boiling, — Three 
points require attention : (1) The amount and nature of the driers ; 
(2) the temperature of boiling, and (3) its duration. When working 
with naked fire, the quantity of drier varies from 2 to 4 per cent, of 
lead compounds and 1 to 2 per cent, of hydrated oxide of manganese. 
The deposit which forms at the bottom of the pan consists of a 
viscous mud, and when a drier with a lead base has been used, we 
also find a notable quantity of metallic lead, whilst the boiled oil itself 
only contains about 1 per cent, of oxide of lead. It follows : (1) 
That the oxidisable principles of the oil have reduced a certain 
quantity of oxide of lead ; (2) that a certain quantity of oxide of lead 
is thrown dowA in the form of lead salts insoluble in oil ; (3) that a 
part of the oxide of lead enters into a soluble combination with the 
oil; this combination takes place by the simple saponification of 
certain glycerides of the oil, and consequently a corresponding 
quantity of glycerine is liberated. These different reactions are set 
up from the commencement at a moderate temperature. In the 
case where manganese is employed instead of lead, the boiled oil 
contains about ^ per cent, of oxide of manganese. 

The temperature ought to be regulated between 210° and 228° C. 
(410° to 442'4° F.) so as to get a good boiled oil, because (1) oil when 
heated commences to give off volatile products at about 230° to 236° 
C. (446° to 456*8° F.), with the formation of fatty acids which yield 
oxidation products of inferior quality, requiring longer time to dry. 
When it is required to produce a limpid oil with but little body 



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OIL-BOUilNG THEORETICAL AND PRACTICAL. 53 

(which is not always the case ; take printers' ink, for example), it 
is advisable not to go beyond 230° G. (446° F.). (2) Again, as a 
consequence of the saponification of a small quantity of oil a corre*- 
sponding quantity of glycerine is h berated; now if this glycerine 
remained, in the free state, in the oil the oxidation products would 
never dry perfectly but remain tacky. The glycerine must therefore 
be eUminated ; this result is obtained by prolonged boiling, for the 
glycerine is partially carried away by the volatilisation of certain 
principles of the oil, which are given off in small proportion during 
the whole process, however carefully regulated, and even although 
the temperature remains lower than the temperature of distillation of 
glycerine. Another portion of the glycerine decomposes under the 
action of prolonged heat, either in presence of metallic lead, as found 
at the end of the operation, or into volatile products such as acrolein, 
aoryhc, formic, or acetic acids, and finally the larger quantity reacts 
upon the triglycerides of the oil, forming diglycerides which after- 
wards oxidise and dry perfectly. Now this latter reaction in which 
one molecule of free glycerine combines with one molecule of a 
triglyceride to form two molecules of a diglyceride, says Livache, 
occurs at 200° C. (392° F.). As a consequence of these facts, he says, 
it follows that to get good results the temperature should not be 
allowed to get below 200° C. (392° F.) nor rise to 230° C. (446° F.). 
In actual practice a temperature of 220° and 228° C. (428° to 442*4° 
F.) is aimed at. 

Finally, the process lasts from three to six hours according to 
the size and shape of the pan, and the manner in which the furnace 
is built on which the pan is heated. The oil ought to be boiled long 
enough for the above reactions to take place, but the boiled oil ob- 
tained as a final result will be better in quality the longer it has been 
boiled, for on prolonged boiling a polymerisation of the glycerides 
takes place, giving a final product which oxidises more rapidly and 
is very elastic after drying. According to Livache, this is the reason 
why in England, instead of boiling rapidly so as to " break " the oil 
as in France, the operation is carried on very slowly at the lowest 
possible temperature, the boiling proceeding for several days, some- 
times for even a week. But, as already mentioned, the fire boiling 
of oil is long out of date in Britain. 

When the oil is boiled by superheated steam, or superheated air, 
the temperature is regulated between 125° and 130° G. (257° to 266° 
F.). When working with steam, the latter is superheated to 4 or 5 
atmospheres, relaxing in the steam coil or jacket to about 2 atmo- 
spheres. It will be readily understood, looking at the matter from 
the double point of view of safety and economy, how difficult it would 
be to superheat the steam to such a temperature that the steam in 
the coil or the jacket would be at 200° G. (392° F.), because it would 
be necessary to heat the oil to 15 atmospheres. Consequently the 
liberated glycerine remains to a larger extent in the oil, and thus 
prevents it from drying so well as fire-boiled oil. However, as the 

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54 



MANUFACTURE OF VARNISHES. 



oil boiled in this way has the advantage of being very pale, endeavours 
have been made to get over the difi&onlty, either by using a larger 
proportion of manganese drier, so as to have a more energetic oxida- 
tion and thereby a spHtting up of the glycerine, or, preferably, by 
producing direct oxidation by a current of hot air, or finally, by 
causing a current of air to circulate through the whole mass of heated 
oil ; or by projecting on the surface of the oil a small quantity of 
water so as to carry away the glycerine in its train. However this 

may be, it is most likely that we have 
here the reason why many persons in 
the trade prefer oil boiled by fire-heat. 
Nevertheless, prolonged boiling by steam 
diminishes and even does away alto- 
gether with this disadvantage. 

Clarification of Boiled Oil. — ^When 
the boiling is finished the oil contains 
suspended solid matter — coagulated or 
carbonised organic matter, insoluble 
salts, undecomposed or unreduced drier, 
etc. In order to hasten deposition the 
oil ought to be left to rest as hot as 
possible, because it is then more fluid 
and limpid, thus facilitating the more 
rapid deposition of extraneous matter. 
It should therefore be run from the 
boiling pan into the settling tanks as 
soon as the steam is turned off the pan. 
When working with small pans which 
can be easily handled, all that has to be 
done is to lift them off the fire and to 
let them stand for eight days at least. 
On the other hand, when working with 
large-sized pans built in masonry, they 
^ ^^''^•2i--ClarificationofOUs ^^^^ ^e emptied quickly, either by a 
by Deposition. Tank for storing , ,, , ^ ^ , . -ii 

oil, showing conical arrangement ladle or by a pump, as hot as possible, 
for deposition of foots and draw- into a reservoir of the same size, where 
off cocks at different heights, j^ ^ j^f^ ^^ deposit for a fortnight at 
(Donovan & Co., Ltd.) i x tt -i. v i j j.i_ x 

least. Here it may be remarked that 

there need be no difficulty in drawing hot oil from one vessel at a 
certain level to another vessel at a lower level by means of a lead- 
pipe syphon, which should be perfectly dry and filled with warm oil 
and held in the hands by a piece of stout felt if it be desired to touch 
it after it is set. In setting it the charged syphon should be brought 
as close to the surface of the hot oil as possible before letting go, or 
the end of the syphon may be plugged up and the plug driven out after 
it has entered the oil. After standing for a fortnight the decanted oil 
may be sent into the market. If stored too long before being used, the 
oil, at first limpid, becomes cloudy, or at least dull, when knocked 




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OIL-BOILING — THEORETICAL AND PRACTICAL. 55 

About in moving or transported in barrels. This is due to chemical 
changes, which supervene slowly throughout the mass. All that has 
to be done is to allow the oil to stand for a day or two after it has 
reached its destination, and to decant cautiously. The amount of de- 
posit formed in this way should not exceed 1 to 2 per cent, of the oil. 

Some oil boilers, who ought to have known better, have been 
known to fill the boiled oil into drums for despatch abroad after 
scarcely twenty-four hours' settling, and that after boiling with 10 
per cent, of cotton-seed oil ! It need scarcely be remarked that 
goods made in this way are liable to be returned, and orders lost 
never to be regained. 

When cotton-seed oil is cheaper than linseed oil it is sometimes 
attempted to boil it in the proportion of 10 to 20 per cent, with 
linseed oil. An oil produced in this way will never clarify, leaving 
altogether out of account its diminished drying properties. Its very 
questionable recommendation is that it is an excellent way of pro- 
ducing a superabundance of boiled-oil foots. Cotton-seed oil is, in fact, 
only classified as a drying oil to fit in with the ideas of theoretical 
chemists, who would fain make practice and actual facts subservient 
to theory. They choose to ignore the fact that stearine abounds in 
cotton-seed oil, and that nothing will prevent the stearate of lead 
and manganese from continuously settling out ad infinitum. 

The very prolonged storing of boiled oil, far from improving it, 
deteriorates it, especially in the case of lead-boiled oil. After from 
five to ten years the oil separates into two fractions, the one solid 
and brittle, whilst the other, retaining its fluidity, can still be used. 
Oils containing manganese alone do not alter in this way. The 
deposit formed during oil boiling varies, according to the quality 
of the oil and the boiling process adopted, from 5 to 8 per cent, 
of the quantity of oil treated. It is of medium consistency, and, 
according to the quality of the oil, the colour varies from white 
to yellow. And^s states that impure, bad quality oil gives a white or 
yellow deposit, whilst well-purified good oil yields a brown one, with 
no granular or crystalline appearance. The loss in oil hqiling and 
the cost may be compensated by adding 2 or 3 per cent, of thick rosin 
oil to the raw oil before boiling. This percentage does not affect the 
finished oil to any great extent. If the boiling process has been well 
conducted, i.e., at a temperature not exceeding 220° C, this deposit 
constitutes the only loss. It is carefully collected, being worth 
sometimes as much as 50 to 60 per cent, of the oil used. It finds 
a use in the manufacture of mastic (cements), soap and low-quality 
paints, especially low-quality blacks, the tint of which it does not 
injure, whilst it greatly improves their naturally bad drying properties. 

Properties op Boiled Linseed Oil. 

Colour and Fluidity, — If we take linseed oil as the type of a 
drying oil, it ought after boiling to be a little less fluid than the 
raw oil, and vary in colour from pale yellow to deep yellow, or, 

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66 MANUFACTURE OF VARNISHES. 

at the furthest, reddish brown. Smell. — The smell, without being 
pleasant, should not be nauseous. Taste. — Taste similar to that 
of the raw oil, bringing to mind the vapours given off during 
boiling. A pungent bitter after taste on the back part of the palate 
indicates rosin oil. Density. — According to Livache, an oil marking 
29° with the Fisher and Bex's oleometer, equal to a density of 
•9325, will register, on the other hand, after being well boiled with 
lead, 24°, equal to a density of '9433, or after boiling with manganese, 
26°, equal to a density of '9389. But the density of a very good 
boiled oil made on the large scale in England according to Vincent's 
process, and drying to a non-tacky, firm, elastic, durable coating in 
six or seven hours in fine weather, and containing 10 per cent, of 
rosin oil, but no other impurity, has always been found to have 
a density not exceeding '934, and if the process be well conducted 
the oil in question will dry in six or seven hours in summer, and 
about ten in winter. Those writers who get in raptures over a 
boiled oil drying in twenty-four to forty-eight hours simply make 
themselves ridiculous. 

Driers : Detection of. — To detect in a boiled oil the substances 
used as driers, Livache gives the following methods : A small 
quantity of the oil is poured into a test tube and shaken with 
dilute sulphuric acid. A white precipitate becoming black on the 
addition of sulphuretted hydrogen indicates lead. If no precipita- 
tion takes place, and if the sulphuric acid becomes green, blackening 
by the addition of sulphuretted hydrogen, the oil contains copper 
compounds. When sulphuric acid gives no precipitate, if the acid 
be neutralised by ammonia on adding ammonium sulphide, iron gives 
a black, manganese a flesh, and zinc a white-coloured precipitate ; 
further, in the case of zinc, the acid solution gives a white precipitate 
with ammonia, soluble in excess. If, instead of using ammonia, we 
neutralise with carbonate of soda, iron yields a green precipitate, 
blackening in the air, and the original solution becomes blue on the 
addition of yellow prussiate of potash ; manganese gives a white 
precipitate blackening in the air. 

Ignition Method. — The better plan is, however, to burn the oil 
with the usual precautions observed in the ash determination of 
vegetable substances, and after weighing the residue on ignition to 
make a systematic qualitative and then a quantitative examination 
thereof. Zinc oxides and salts are, however, liable to volatilise and 
escape recognition. The methods given for the determination of 
mineral substances in oils in books devoted to the chemical analysis 
of oils are quite unreliable, and none more so than those of Bene- 
dikt. A systematic examination of the ash is the only reliable 
niethod. It is most unscientific to estimate lime in the analysis 
of the ash of oil in the same way as is done in the case of marble ; 
we know beforehand that the marble is almost chemically pure 
carbonate of lime. As to the ash of an oil we know nothing what- 
ever, and to proceed to its analysis with preconceived notions shows 
very bad training on the part of the analyst, whoever he may be. , 

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CHAPTEE III. 

LINOLEUM MANUFACTURE. 

Thickening of Linseed Oil by Oxidation, — Whatever process we 
may adopt in the boiling of oil, the consistency or body of the re- 
sultant product is but little different from that of raw oil. Now, in 
many cases it is very advantageous to use an oil of good body, so as 
either to hasten the drying when it is used either directly or after it 
has been incorporated with varnish, or when it is desired to apply the 
oil to porous surfaces, wood, etc., without having reason to fear of 
its being imbibed by such substances. The simplest procesa consists 
in causing the oil to fall in a thin layer, in contact with air, as we 
have seen in the cold process of making drying oils (p. 32), but the 
process is a long one, and oxidation becomes difficult as soon as the 
oil attains a certain thickness, even when working at a temperature of 
50° to 60° G. (122° to 140° F.), by which the oU is kept fluid for a 
longer time. Further, a quantity of oil adheres to the plates, and 
there solidifies, causing a serious loss when it is not desired to con- 
vert the whole into a solid body. Finally, after a time a solid 
pellicle is formed on the surface of the oil, which prevents oxidation, 
and consequently the thickening from proceeding through the mass 
of oil. 

Attempts have been made to increase the fluidity of the oil artifi- 
cially by dilution with a suitable solvent. By taking, e.g., equal parts 
of manganese- boiled oil and benzine, and stirring the mixture in a 
closed vessel, with simultaneous injection of air, rapid absorption of 
oxygen takes place. This absorption is stimulated by aid of heat 
regulated between 40° and 50° G. (104° to 122° F.). If the air be 
continuously injected so as to supply the quantity of oxygen necessary 
for complete oxidation of the oil, a quantity which amounts at least 
to 16 per cent, by weight of the oil used, the mixture soon thickens, 
and if finally we distil off the solvent a viscous residue is left on cool- 
ing. If the process be carried on so as to completely oxidise the oil, 
the liquid becomes cloudy owing to the formation of linoxin, which is 
insoluble in benzine ; on separating the latter, the linoxin is obtained 
as a very dry, elastic solid. In actual practice boiling is continued 
for a long time, often for three or four days, and the temperature 
pushed as far as 250° to 300° G. (482° to 572° F.). By this means 
heavy bodied oils are produced, which can be thinned down by the 

(57) ^ , 

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68 



MANUFACTUEE OF VARNISHES. 



addition of thinner bodied oil, boiled only from six to eight hours at 
200° C. (392° F.). But boiling at so high a temperature has the dis- 
advantage of liberating fatty acids, which take longer to oxidise, and 
render the oil fatty. In England and Germany preference is given to 
boiling pil by superheated steam or superheated air either in pans as 
flat as possible, so that the surrounding air may have free access, or 
in deep, closed pans, into which either cold or hot air is injected. In 
certain manufactories, especially in Holland, no drier is used ; it is 
considered preferable to oxidise the oil exclusively by the injection 
of hot or cold air. The product is superior, but the process rather 

slow. S. Lewiak has taken out a 
patent for the injection of hot air 
in the production of linoleum, No. 
14518, 1903. 

Storage of High -class Boiled 
Oil, — According to Livache, when 
a choice boiled or thickened oil is 
manufactured, it should not be 
stored either in iron or copper 
vessels without electro-^plating the 
interior with silver ; this deposit 
need not be thick, as it is subject 
to no wear and tear, and owing to 
the low price of silver would not 
be so costly as would at first sight 
appear. The same result may be 
arrived at, viz,, prevention of dis- 
coloration by a layer of enamel 
which stands well and is economical. 
Wrought-iron vessels ** galvanised "^ 
Plant. AA. vessels containing oil com- on the inside Surface with tea lead 
municating through B ; H, reservoir which contains tin have no action 
with perforated bottom ; N, pipe V7ith q^ boiled oil, varnish, nor on spirits 
upv7ard current of air ; D, downward - . i.r\ x / a* 

shower of oil ; C, chimney-stalk ; E, air ot turpentme. One per cent, of tm 
pressure equaliser ; F, pump. added to the lead has the same 

effect. 
Walton's Processes. — In F. Walton's, Lion's, Hadfield's and other 
processes, air is made to act upon oil falling in drops, in such a 
manner as to present a large surface to oxidation. The modus oper- 
andi of such processes will be understood from Fig. 22. Walton's 
plant is composed of a reservoir, the bottom of which, pierced with 
a number of holes, rests upon a second rectangular reservoir, of which 
two of the faces are made of glass so that the action of sunlight may 
intervene with the view of stimulating oxidation and bleaching the 
oil ; the other two faces are made of perforated sheet zinc ; through 
one of these faces air enters, the whole way up the column, and 
passes out through the other, but owing to the minuteness of the 
holes and to their conical shape the oil is retained. This quadran- 




FiQ. 22. — Linseed Oil Oxidation 



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LINOLEUM MANUFACTURE. 69 

gular column is itself surrounded by a double envelope made either 
totally of glass, or having two faces at least of that material, and in 
which an arrangement of partitions causes a current of air to flow 
against one of the perforated zinc faces and to force its way through 
the opposite. This current should not be too strong, but yet strong 
enough to constantly renew the air in contact with the oil. 

The oil at last falls into a steam- jacketed reservoir, A, by means 
of which it can be heated to a temperature between 100° and 170° C* 
(212° to 338° R). Finally, by means of a pump simUar to Fig. 22, 
F, the oil thus heated is propelled into the reservoir at the top of the 
column, through the openings of which it again passes to be sub- 
mitted afresh to the action of the air. An automatic arrangement 
enables the flow of oil to be stopped should the pressure inside the 
column become too strong. Eaw oil, to which an appropriate drier 
has been added at the start, is that which is generally treated with 
this apparatus. Sugar of lead to the extent of 5 to 10 per cent, is the 
most suitable drier. However, oil previously boiled with manganese 
or litharge may also be treated, but air is propelled in this case at a 
lower temperature, say, 100° G. (212° F.) ; nevertheless, in spite of 
this precaution, the resultant oil is darker than when raw oil is used. 
Another arrangement by Walton consists in boiling the oil in large 
open pans ; the hot oil is led into a chamber maintained at a suitable 
temperature by steam pipes. Here the oil which falls on the floor 
of the chamber is beaten with armed agitators, bringing it into the 
form of a spray which meets a current of air passing in the opposite 
direction ; the oil falls back again into the chamber, which may be 
covered with glass,, so that the action of sunhght may intervene. 

Storer*s Process. — Instead of blowing air into the oil, Dr. John 
Storer draws it in from the atmosphere by suction by the creation 
of a vortex current generated by a sort of screw propeller. By a 
mechanical airangement the oil subjected to the vortex action flows, 
into another compartment and returns to the surface to expel the 
vitiated air and to be again and again subjected to the same treatment. 
The screw propeller makes about 1,500 revolutions a minute. It will 
readily be seen that by the commingling of continually renewed fresh 
air, drier and oil are affected in a most complete and perfect manner 
by this process. The plant differs from Vincent's in the fact that the 
fumes are carried away, not by a dome riveted to the pan and form- 
ing part of it, but by a hood suspended over the pan, thus allowing 
fresh air to be continually brought in contact with the oil without the 
necessity of pumping. The atmosphere above the pan is therefore 
always freer from decomposition products. 

Solidificatio'n of Boiled Oil — Linoleum Manufacture, — When boiled 
oil is completely oxidised it is insoluble not only in ordinary boiled oil 
itself, but also in the whole of the various solvents used as thinners,, 
consequently manufacturers generally are content with a partially 
oxidised product which will dissolve therein. 

But nowadays there is a demand for completely oxidised and 



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60 MANUFACTURE OF VABNISHES. 

consequently solid oils, which are incorporated by miidng and grind- 
ing with a great number of substances, to which they impart im- 
permeabiUty, elasticity, as well as insolubility, not only in the various 
solvents for oil but also in acids. This is the case in the manufacture 
of linoleum, for example, and other similar substances formed by a 
mixture of solid linseed oil, powdered cork, sawdust and rosin. The 
process most generally adopted consists in spreading in a very thin 
layer boiled oil, or oil thickened after one of the processes described, 
80 that it may be completely oxidised ; if the layer be too thick 
a skin is formed on the surface when oxidation verges completion, 
which stops all further oxidation from going on underneath, and com- 
plete solidification is prevented. When large quantities of solid oil 
are required it is necessary to have enormous surfaces at disposal, so 
that the layer of oil to be oxidised may be as thin as possible. Two 
methods are in vogue : (1) Linen cloths are passed through a bath 
of the oil to be oxidised, and thus become impregnated with the oil, 
and are afterwards suspended vertically so that the excess of oil 
drops ofif. When the layer of oil is dry the Unen is passed through 
the bath once more and thus becomes charged afresh with oil, and 
again vertically exposed to the action of the air, and so on until a 
succession of solidified layers gives the thickness desired ; (2) the 
following is a more simple arrangement. Oil is made to fall upon 
several thousand square yards of Hnen suspended vertically. The 
oil being in a very thin layer absorbs the oxygen necessary to change 
it to the solid condition very rapidly. This absorption is facilitated 
by working in warm chambers. The sequence of operations which 
follow each other, almost automatically produces, very cheaply, a 
superposition of perfectly dry pellicles, amalgamated together to form 
a mass of considerable thickness. To separate the sohd oil from the 
linen, the latter is passed between two rolls heated by steam, and so 
adjusted that only the linen can pass through. In starting all that 
has to be done is to free the linen from solidified oil for about an inch, 
and feed it in between the rolls ; these catch hold of the linen and 
draw it forward, leaving the solid oil behind. The Unen may thus 
be used over again to prepare a fresh batch of solid oil. But when 
complex substances are to be made from the solid oil, manufacturers 
do not trouble to separate the two, the more so as the linen does not 
last long. In that case the linen charged with oil is ground up and 
mixed with the other ingredients. 

Livache tried to use this oxidised oil by itself. When triturated 
w^ith the majority of volatile solvents, spirits of turpentine, benzine, 
alcohol, ether, bisulphide of carbon, etc., it swells, becomes trans- 
parent and then divides into pieces of extreme tenuity, and thus forms 
a paste which may be spread out in a more or less thick layer. When 
the solvent has evaporated, an elastic homogeneous surface of oxidised 
oil is obtained, perfectly dry and of appreciable thickness. These 
pastes of oxidised oil may be combined with caoutchouc pastes, or 
with solutions of india-rubber and other substances, soluble in the 



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LINOLEUM MANUFACTURE. 



61 



solvents used, so as to obtain after evaporation a homogeneous product 
of peculiar properties partaking of those of the different substances 
entering into its composition. 

The oil treated in the manner described until the maximum 
ainount of oxygen has been absorbed, forms a gelatinous mass denser 
than water which can be drawn into strings. It is insoluble in 
alcohol, ether, spirits of turpentine, chloroform and carbon disulphide. 
When mixed with cork dust and rosin, ** fillers," etc., it is rolled 
into linoleum. The highly -complicated machinery for inlaid linoleum^ 
etc., is beyond the scope of this work. The following elementary ana- 
lyses are by Eowland Williams : — 

Elementary Analyses op Oxidised Oils for Linoleum 
Manufacture. 





Raw Linseed. 


Oxidised Linseed Oil for Linoleum Manufacture. 


1 


2 


3 


4 


5 


6 


7 


8 


9 




7o 


°/o 


°/o 


°/o 


7o 


Vo 


°/o 


/o 


7n 


Carbon 


7603 


75-40 


74-82 


69-74 


69-52 


64-74 


65-40 


68-64 


64-38 


Hydrogen - 


10-78 


10-64 


1004 


9-57 


9-49 


9-01 


9-00 


9-24 


9-01 


Oxygen - 


14-19 


18-96 


16-64 


20-69 


20-99 


26-25 


25-60 


22-12 


26-61 



Beh's Process, — Good clarified Eussian linseed oil is boiled with 
nitric acid of known strength to decompose the glycerine and oxidise 
the oil. The oil treated in this way is pumped into a tank waggon 
which sprinkles it on to a cloth which is oxidised by hot air. 

Herkhorns Patent. — In this process the alkaline earths and their 
soaps are added to the oil dm:ing boiling and oxidation, and a velvet 
lustre is thereby imparted to the mass. Eosin and rosinate of 
magnesia are added to the oil. 

Pinette analysed three samples of linoleum with the following 
results. His method of working is so obvious as to require no 
description. 

Analyses op Linoleum. 



Water 

Linseed Oil Soluble in Ether 

Linseed Oil Insoluble in Ether (Cork, Oxidised Oil) 

Silica 

Ferric Oxide 

Alumina 

Lime 

Alkalies --- 



3-39 
11-43 
77-24 
2-94 
1-78 
1-91 

1-31 



3-01 
10-60 
73-63 
3-99 
1-79 
4-94 

2-04 



3-41 
19-58 
54-16 
4-31 
8-86 
0-61 
6-17 
2-90 



100-00 



100-00 



100-00 



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CHAPTER IV, 

PRINTING INK MANUFACTURE. 

Printing and Lithographic Ink, — The chief ingredient of printing 
ink is boiled oil, most generally linseed, sometimes hemp-seed, which 
is cheaper, but has a bad smell. No attempt is made to produce a 
fluid quick-drying oil like that used in the manufacture of oil 
varnishes, viz,, by boiling the oil to a temperature not exceeding 220° 
C. On the contrary, we have to produce a partially resinified, parti- 
ally decomposed oil which will leave no greasy stain on paper by 
heating the oil above 250° C. 

Befining Oil for Printing Ink, — The old tanked oil used should be 
of prime quality, so as to avoid the disagreeable smell and too deep 
colour of ordinary oil. It ought to be tanked for at least a year or 
two, so that all solid impurities may have completely separated out. 
In other words, what is known as old tanked oil should be used, 
but it ought still to undergo a special refining with sulphuric acid. 
Accordingly the oil is mixed with 1 or 2 per cent, of sulphuric acid 
of about 103° Tw., sp. gr. 1*515, and heated for several hours by 
means of a steam coil to a temperature of 90° C, taking care not to 
go beyond 100° C. The oil is then pumped into another tank con- 
taining hot water, with which it is well washed, running off the wash 
water and agitating afresh, and so on until all trace of acid is 
removed. The oil may then be boiled. As drying oils contain a 
certain quantity of fatty matter (palmitin) which does not dry, and 
causes the printing ink to blot or blur, it has been recommended to 
eliminate it by adding to every 1,000 parts of oil 1 or 2 parts of 
fuming nitric acid, which decomposes the palmitin into glycerine and 
palmitic acid, which may thus be precipitated as insoluble palmitate 
of lead or manganese. This process seems, however, to present 
many difficulties, which have prevented it from being adopted to any 
extent. Moreover, fuming nitric acid, in consequence of being easily 
decomposed, is by itself a dangerous substance ; this danger is 
intensified to the highest degree when the acid is mixed with organic 
matter. Dangerous explosions may result and the oil take fire. 

Description of Pan, — The oil is boiled either in a cylindrical 
copper pan, the lower half of which fits into the brickwork of the 
furnace, where it is kept in position by a collar which at the same 
time acts as a gutter to collect any overflow, or in a cast-iron 

(62) 



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FEINTING INK MANUFACTURE. 63 

enamelled pan. The pan is manipulated with a chain or by an iron 
band encircling its top, and attached to which are strong arms, by 
means of which it can be moved with safety. The capacity is 60 to 
85 gallons. But in certain important factories the boiling is done in 
jacketed pans which do not cube less than 600 to 700 gallons. In 
such cases a mechanical agitator is kept going during the boiling 
process, which may last two or three days. (See Figs. 18-20.) 

Boiling Process, — The pan is filled to half or at most three- 
quarters of its capacity, and a moderate heat applied so as to get quit 
of all trace of moisture ; when the boiling goes on quietly the fire is 
quickened imtil volatile, pungent and disagreeable smelling products 
are given off. This takes place at a temperature of 250° to 270° C, 
(482° to 518° F.). In certain factories the workman satisfies himself 
as to this being the case by dipping in organic matter, such as a 
feather, for instance, which ought to inflame ; or by projecting fine 
drops of water on to the surface of the oil, which as they fall 
decompose and scintillate, or, in other words, present, in consequence 
of the absorption of oxygen by the oil and the inflammation of the 
hydrogen, the appearance of stars. The fire is now carefully watched, 
for the oil may froth over or the vapours ignite. The frothing over 
is parried by adding a little cold oil. The oil becomes bright and 
more fluid at first, but, on being kept at this temperature for one or 
two hours, a brown red skin forms on the surface, which is skimmed 
off as rapidly as possible, because it is this skin which colours the oil 
brown. The temperature is now raised to 810° C, and kept at that 
for half an hour to an hour, watching the process with the greatest 
of care, as the vapours are very apt to catch fire. A well-fitting lid 
and wet cloths ought therefore to be always at hand. The fire is 
now allowed to die down, so that the temperature may descend to 
260° to 270° C, when the pan is withdrawn from the fire. It is 
covered with a lid, and let stand to cool. Certain makers, instead of 
cooling the oil after withdrawing it from the furnace, set fire to the 
fumes, and let them burn for about five minutes — an operation they 
regard as indispensable in the production of a good article. Others 
contend that the same result is got by boiling the oil a little longer, 
which saves the appreciable loss of oil incurred by burning, and a 
much paler oil is obtained. 

" String " Test — ^The exact moment when the pan ought to be 
removed from the fire is determined by the " string " test. A small 
sample of oil is taken from the pan on an iron spatula, and is cooled 
rapidly by stirring it. A drop is taken and pressed between the 
finger and thumb, which are then gradually drawn apart as far as 
possible. The thread joining the finger and thumb together should 
stretch 1 to 2 inches without breaking, otherwise the oil is not suffi- 
ciently boiled. 

Properties of Good Printing Ink. — Good printing ink has the 
requisite body of a pale, bright yellow colour — not deep yellow or 
brown — and is not cloudy from matters in suspension. It is very 



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64 MANUFACTURE OF VARNISHES. 

evident that the body of the oil will depend upon the purpose for 
which it is intended. For printing books and lithographic work an 
oil having a good body is required, whilst for newspaper printing a 
soft, almost fluid oil is used. According to Villon, who made an 
elaborate study of printing ink, five kinds of oil of dififerent body or 
consistency are in the market, viz, : — 

(1) Extra strong, (2) strong, (3) medium and (4) weak-bodied 
oils, and (5) drying oil. The strong- bodied oil (2) is used in summer 
for very particular work with the hand press. The medium oil (3) 
is used in ordinary weather. The weak-bodied oil (4) is used in 
winter with the mechanical press, whilst the drying oil (6) is used to 
prevent the formation of the oily ring around the letters. 

Driers and Extra Strong-Bodied Oil. — Usually no driers are« 
used, becatise oil boiled with driers would clog the type, and could not. 
be removed even when washed with a hot alkaline solution. There 
is sometimes, however, an advantage in using such an oil, and to- 
meet this want the oils known as " extra strong " and " drying " oila 
are manufactured. 

The " extra strong- bodied " oil is made by boiling with lead salts,, 
and the ** drying" oil by boiling with an oxide or salt of manganese. 

Siron^ -bodied oil (2) (huile forte) is prepared by setting fire to the 
oil, letting it burn for five minutes, and stirring several times. The 
flames are put out and the oil again set on fire, twice at least, and 
sometimes four times. The cooled oil strings like treacle. The 
*' fatty " oil is made by shortening the burning process, and is inter- 
mediate between the other two. Nowadays a process similar to that 
used in making ordinary printing ink is adopted. The removal of 
grease by onions or bread is then effected by nitric acid, as previously 
indicated, or by magnesia. This latter, which is extensively used in 
England, consists in adding 2 per cent, of magnesia, boiling for an 
hour, and decanting. The oil is then run into a pan capable of hold- 
ing 42 gallons, and gradually heated to 182° C. (327*6° F.), three 
hours being occupied in attaining this point. About li lb. of finely 
ground bichromate of potash is then added, and the temperature is. 
raised to 300° C. (572° F.), stopping the frothing of the oil by adding 
a little cold oil, then it is kept for half an hour at a temperature 
between 315° and 320° C. (599° to 608° F.), after 11 lb. of Prussian 
blue have been slowly added. " Strong "-bodied oil is thus obtained. 
To make *' fatty " oil, the oil is only heated for five minutes to 300° to 
305° C. (572° to 581° F.). With ** pale " oil the heat does not rise 
above 275° C. (527° F.), which is maintained a quarter to half an hour,, 
according to the object in view. 

The " extra strong- bodied " is added to the '* strong- bodied " oil.. 
The former is made by heating to 150° C. for an hour. 

Lb. 
Linseed oil •-•---•-- 200 
Litharge ---•••---• 5 

Umber ----••---- 4 

White lead 2 



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PRINTING INK MANUFACTURE. 65 

The drying property of this boiled oil is tested by spreading it on 
a glass plate, when it should be perfectly dry next day, with neither 
air-bells nor dulness. If it be dull 5 per cent, of spirits of turpentine 
must be added. 

The " drying oil " is obtained by heating for fifteen hours at 275° 
C. oil to which 0*05 per cent, of the hydrated oxide of manganese has 
been added, or by boiling oil for twenty-four hours at 300° C. (572* 
F.), with 5 per cent, of black oxide of manganese. If borate of man- 
ganese be used 4 lb. of this salt are beaten up with 25 lb. of linseed 
oil, and run into 2,000 lb. of linseed oil, and the whole heated for 
half an hour at 250° C. (482° F.), or a quarter of an hour at 316° C. 
(620*8° F.). Some manufacturers add 2 J per cent, of oxalate of 
manganese, whilst applying heat for three hours at 150° to 160° C. 
(302° to 320° F.), or simply add a manganese soap (manganese 
linoleate) previously dissolved in coal-tar naphtha, petroleum ether, 
or spirits of turpentine. 

Use of Bosin. — When great body is required, without having re- 
source to prolonged boiling, rosin may be added. Bosin is, in fact, 
extensively used in the making of printing ink, forming with the oil 
a mixture not unlike Canada balsam in appearance and consistency, 
and the latter itself is one of the best vehicles that can be used. 
With ordinary black ink common rosin is used, but for fine, coloured 
inks pale Aijigkeriqan rosin is employed. The rosin is melted, filtered 
to eliminate rubbish, and added to the oil during boiling. When 
very high-class inks are required for jobs to be executed in an especi- 
ally neat and delicate manner, balsam of Peru, Canada balsam, or 
copaiba balsam are used instead of rosin. Copaiba balsam is said to 
produce a good extemporaneous ink when mixed with the proper 
quantity of soap and pigment. 

Use of Soap. — Finally, a certain quantity of soap is added to the 
oil, which imparts suppleness, but its principal object is to facilitate 
the cleansing of the type, enabling this to be done with a brush. 
The soap ought to be perfectly dry, that is, to have been left for a 
long time in thin shoes at 100° C. (212° F.), until it ceases to lose 
weight. Ordinary yellow rosin soap is used for common black ink, 
but for fine inks, for light and delicate shades of colour, white curd 
soap is used. Too large a proportion of soap retards drying and 
gives rise to irregular printing. The printing-ink maker should only 
use as much soap and no more as will cause the ink to work clean 
and without clogging the type. 

Blue Black Ink. — A little indigo blue is also added to the hot oil 
to impart lustre, or 1 per cent, of Prussian blue may be added as the 
oil commences to boil, which, as it dissolves, yields a beautiful blue 
black. 

Manufactwre Proper. — Generally in the actual manufacture of the 
ink, the boiled oil is moderately heated with the simple addition of 
rosin and soap alone until the mass becomes tranquil and homo- 
geneous; the colour is then added and ground in the mill until 

5 

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66 MANUFACTURE OF VARNISHES. 

perfectly cold. Another process consists in melting the rosin until 
destructive distillation commences, then to add soap in slices, and 
then the boiled oil. Heat is now applied more strongly, so as to in- 
crease the fluidity of the mass, then the colour is added, and the 
whole run into a receiver, from whence it passes to the mill while 
still hot. The nature and the quantity of the colouring matter de- 
pend upon the consistency of the oil and the object in view, but 
heavy, dense, mineral colours should, as far as possible, be excluded, 
using in preference light colours, which give a more homogeneous 
and impalpable ink. 

Thus the following colours are hajbitually used, viz,, for 

Black — Lamp-black. This pigment may be used alone or with 
an equal weight of Prussian blue for the purpose of removing the 
brown tone of certain lamp-blacks. Bone black is too dense to be 
used by itself. It is, however, added in small quantities to lamp- 
black so as to produce an ink for printing wood engravings. Carbon 
gas black is a magnificent colour. 

Bed — Lake, cochineal, carmine, aniline lakes ; very rarely red lead 
or vermilion. Vermilionette, containing 90 to 98 per cent, of a mixture 
of red lead and barytes, is too heavy and dense. 

Lakes made with tannic acid go leathery in oil. 

Blice — Prussian blue or indigo ; a rich tone is got by grinding a 
little Indian red, FcgOs, with the Prussian blue and indigo; ultra- 
marine is inadmissible as it is easily bleached. 

Yellow — Yellow ochre or chrome yellow, chinoline and other 
aniline lakes. 

Green — Mixtures of blue and yellow. 

Brown — Sienna and umber. 

The printer or printing-ink maker could not do better than con- 
sult Jennison, Lake Pigments (Scott, Greenwood & Co.). Samples 
of colour printing produced by lakes of all colours and shades of 
colour are given therein, with instructions how to make them. 

Charaotebistios op Good Printing Ink. 

Printing ink ought to satisfy several tests, (a) It ought to be 
perfectly homogeneous, for the least particle of extraneous matter 
(grit, etc.) will cause a blot in the printing ; {h) it should not alter 
when exposed to the air in bulk for a long time, but when spread in 
a thin layer it should dry very quickly, without, however, commenc- 
ing to do so on the type, from which it should be easily removed by 
washing; (c) the colour of dry printing ink should be rich and 
brilliant ; {d) it should not penetrate the paper too deeply but deep 
enough to prevent it being detached from the surface ; {e) finally, it 
ought to have no bad smell. 

The proportions of different substances entering into the composi- 
tion of printing ink vary much. They may, however, be reduced Jo 
three types : — 



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PRINTING INK MANTJFACTTJRB. 



67 



Best. Medium. Ordinary. 

Lb. Lb. Lb. 

Boiled oil 100 100 100 

Rosin 26 50 76 

Soap - 4 6 8 

Drying oil 6 9 12 

For ordinary, such as newspaper, work great economy is neces- 
sary, hence in place of boiled oil there has been used a mixture of 
raw oil and thickened turpentine ; the quantity of rosin is increased 
and the requisite fluidity obtained by the addition of rosin oil. 

The proportions given by And6s are as follows, according to the 
amount of body required : — 

Lb. Lb. Lb. 

Raw linseed oil - - - - 140 110 90 

Rosin oil 240 240 240 

Rosin 210 210 210 

Rosin (i.e., yellow) soap - - - 5. 6 6 

Thickened turpentine ... 5 5 5 ' 

Inferior inks are made very cheaply by replacing linseed oil by 

rosin oil, for which purpose the following recipes have been given : — 

Lb. Lb. 

Rosin oil 1,000 1,000 

Rosin 400 780 

Rosin soap 100 780 

Ordinary soap - 100 180 



GOYNEAU'S PRINTING INK. 





lb. 


lb. 


lb. 


Linseed Oil 


979 


400 


980 


Litharge ... 


125 


60 


122 


Rosin ... - 


735 


880 


980 


Syrup - - 


245 


980 


968 



IL 



1. Venice Turpentine .... 

2. Olein 

8. Soft Soap 

4. Lamp-black 

6. Prussian Blue - - - -\ 

6. Oleic Acid \ 

7. Water J 



lb. 


lb. 


60 


9 


30 


4 


80 


10 


50 


4 




or more 


40 


— 


20 





20 


— 



Mix 1, 2 and 3 with aid of heat. Stir in 4 after sifting finely, then 
incorporate with I. the solution of 5, 6, 7. The 40 lb. of Prussian 
blue may be replaced by 20 of indigo carmine first rubbed up with 
water. It is claimed for II. that it can be removed from old printed 
paper and renders printers* lye unnecessary. 



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68 



MANUFACTURE OF VABNISHBS. 





Common 
Black. 


Rotary 
Soft. 


Jobbing. 


Paraffin Oil 
Rosin - 
Lamp-black 


lb. 
26 
45 
15 


lb. 
26 
40 
16 


lb. 
26 

16 
46 



Eosin of different grades may be used or Burgundy pitch. The 
paraffin oil may be replaced by rosin ; the proportion of lamp-black is 
adjusted accordingly. Other pigments in suitable proportion may be 
substituted for lamp-black. 

GUNTHER'S PRINTING INK. 

Lb. Lb. 

Heavy tar oil 46 28 

Pitch or asphaltum 40 40 

Rosin pitch soap - 12 24 

Fish oil 5-8 — 

Spirit soluble aniline dye in powder - - 3-16 8 

The heavy tar oil is first acted on by chlorine at 212"* F., or. is 
heated with nitric acid to deodorise it. The oil is then boiled with 
5-10 per cent, of chloride of copper, heated to remove free acid, and 
then dissolved in warm water or stirred into the oil to give the oil 
a brownish-black colour and thus reduce the aniline violet to a 
minimum — J per cent, is then sufficient. The oil thus treated can be 
used as a stamping ink for post-office work without any addition. 

PRINTERS' INKS FOR VARIOUS PURPOSES. 



Use. 


Rotary Machines. 


News- 
paper. 


Book. 


Illustration. 


Vehicle - 
Lamp-black - 
Prussian Blue - 
Indigo - 
Chinese Blue - 


lb. 
70 
30 


lb. 
72 
28 


lb. 
72 
28 


lb. 
72 
28 


lb. 
74 
26 


lb. 
74 
26 


lb. 
78 
22 


lb. 
76 
24 


lb. 
77 
28 


lb. 
79 
21 


lb. 
80 
20 


lb. 

78 

20 

2 


lb. 

78 

19 

2 

1 


lb. 
78 
19 

1 

2 



PRINTING INKS— VEHICLES. 





Thm. 


Medium. 


Thick. 




lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


Rosin - - - . 


26 


26 


25 


50 


60 


60 


77 


77 


77 


BoUedOil - - - 


100 


100 


100 


100 


100 


100 


100 


100 


100 


Rosin Soap - 


8 


3 


3 


10 


10 


10 


7 


7 


7 


Weak-boiled Oil - - 


7 


4 


— 


9 


6 


— 


12 


9 


— 



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PRINTING INK MANUFACTURE. 



69 





Thin, 


Medium, 


Thick, 




with Boiled OU. 


with Boiled Oil 


with BoUed OU. 




lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


lb. 


Rosin OU 


60 


60 


60 


60 


60 


60 


60 


60 


60 


Rosin - - - - 


25 


60 


76 


60 


60 


60 


60 


60 


60 


Boiled Oil 


60 


60 


6 


60 


60 


60 


60 


60 


76 


Rosin Soap - - . 


3 


6 


7 


8 


6 


7 


3 


6 


7 


Weak-boiled Oil - 


7 


9 


12 


4 


6 


9 


■— 


— 


— 



PRATT'S ORIGIN ROSIN OIL PRINTING INK VEHICLE. 



Rosin Oil - 
Rosin - 
Yellow Soap 



lb. 


lb. 


20 


60 


8 


39 


2 


9 





Thin. 


Medium. 


Thick. 


Rosin OU . . . - 
Raw Linseed OU - 
Rosin Soap - - - - 
Thick Turpentine - 

Rosin 

Boiled OU - - - . 


lb. 

96 

84 

2 

2 

62 


lb. 
96 

7 

100 
36 


lb. 

240 

210 

6 

6 

1,000 


lb. 
80 

70 

100 
3,600 


lb. 

240 

210 

6 

6 

87 


lb. 
80 

7 

100 
26 



Ink for Steel Engravings. 

This oil, accordiag to Villon, who made a special study of ink for 
steel engravings, is prepared Hke printing ink, the only difference being 
that it is boiled a little longer. Old tanked linseed oil, i.e., well-aged 
oil, is the oil employed, or, better still, walnut oil ; but this latter is 
never used alone, a little hnseed oil, varying from 12 to 50 per cent., 
according to the quality desired, being always added to give it more 
viscosity. The boiling process, although an old one, is that still 
used. It consists in heating 5 gallons of oil in a pot until it takes 
fire or gives off white fumes, which are set on fire. It is left to bum 
for five minutes, taken off the fire and placed on a furnace filled with 
hot ashes, where it is let bum a few minutes longer. A piece of stale 
bread, held by a pair of pliers, is dipped into the oil untU it reddens, 
without, however, charring ; it is replaced by a second slice, and that 
by a third — the bread is sometimes replaced by peeled onions. 
Although no explanation is given of this process, it would appear to 



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70 MANUFACTURE OF VARNISHES. 

be necessary. At any rate practical men think so. The pot is now 
covered and allowed to cool. There is thus obtained a bright, greenish 
oil {huile claire), more consistent than the raw oil, but with no body. 
De Luxe Illustrations, Ink for. — Villon gives the following pro- 
portions for ink to be used in the production of de luxe illustrations : — 

Lb. 

Limpid oil (huile claire) 1,000 

Strong-bodied oil {huile forte) 250 

Lamp-black 600 

Prussian blue 50 

Rosin (yellow) soap 26 

The Prussian blue is first added to the clear oil in a pan fitted 
with a mechanical agitator, and heated to 100° C. (212° F.) by a 
steam jacket. The heat is raised to 150° C. (302° F.), and the rosin 
soap is mixed with continual stirring. It is only when perfectly 
cold iihat the black is introduced into the mixture, then the huile 
forte (strong-bodied oil). The whole is then passed through rollers. 
Small quantities may be ground in a mortar worked by power. [By 
using carbon gas-black instead of ** lamp "-black a superior jet black 
is obtained.] 

Black Ink for Engraving Purposes. — Villon's researches resulted 
in his selection of the following formula as yielding a very black ink 
for engraving purposes, without reddish reflex, and of irreproachable 
composition, which keeps well, and each of the ingredients of which 
plays an important part : — 

Lb. 

Huile claire (pale limpid oil) 1,000 

Huile forte (strong-bodied oil) ----- 200 

Carnanba wax 25 

Paraffin 35 

Yellow soap (rosin) 25 

Paris violet 0*5 

Prussian blue 40 

Cork black 100 

Blood black 50 

Winelees black 200 

Ivory black 150 

Numerous other substances are also used ia impart consistency 
and unctuosity, such as Canada balsam, ozokerit, asphaltum, stearic 
acid. It is for each manufacturer to select those materials best 
adapted for the object in view. THe retention of the copper lustre 
of Prussian bltte in the matter printed from an ink made from that 
pigment is a subject which has interested and engaged the attention 
of not a few. Some claim to have succeeded by the use of lard, etc. 
But the copper bronze reflex of modem printed matter is undoubtedly 
due to nigrosine black and aniline blues. With the use of these 
pigments the difficulty is not in retaining the bronze, it is in eliminat- 
ing it. 



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PRINTING INK MANUFACTURE. 



71 



PRINTING INK VEHICLES.— (Lewkowitsch.) 



ah 



g 3 « 

loo 



IS 



!§1 



11 



Raw Linseed Oil 

Tint - 

Thin - 

Middle 

Strong 

Extra Strong 

Burnt Thin 

Oxidised Oil {weak) 

Oxidised Oil (strong) 

Dried Linseed Oil 



0-9321 

0-9684 

0-9661 

0-9721 

0-9741 

0-9780 

0-9676 

103 

1-06 



0-86 

1-46 

1-76 

1-71 

2-16 

2-61 

6-93 

18-28-4 

18-49-28-9 

12-67 



194-8 

197-6 

196-9 

197-6 

190-9 

188-9 

195-6 

221 

228-6 

171-6 



0-62 
0-86 
0-79 
0-91 
1-35 
0-81 
0-97 
0-81 



0-80 

1-60 

2-60 

4-20 

6-60 

7-60 

0-86 

42-82 

44-19 

31-68 



169-0 
118-2 
100-0 
91-6 
86-7 
88-6 
92-7 
68-8 
68-6 
93-9 



PRINTING INK VEHICLES.— (Lewkowitsch.) 
Mixed Fatty Acids. 





IS 


d 


^ d 


? 


§ 
1 






Is 


Melting 

Point, 

Degrees 


Solidify 

Point, 

Degrees 


Mean 

Combin 

Weight. 


(a 

14 




Raw Linseed Oil 


0-928 


24-26-6 




286-6 


196-8 


146-6 


Tint 


0-941 


20-6 


16 


— 


— 


118-3 


Thin 


0-949 


22 


18 


— 





108-8 


Medium . . - . 


0-950 


24 


22 


272-6 


206-8 


97-7 


Strong - - - _ 


0-963 


25-6 


24 


270-1 


207-7 


87-3 


Extra Strong 


0-966 


27 


23 


269-8 


207-9 


90-8 


Burnt Thin 


— 


23 


19 


— 


— 


99-3 


Oxidised Oil (weak) - 





28 


26 


241-4 


232-4 


63-2 


Oxidised Oil (strong) - 





27 


26 


242-6 


231-3 


60-6 


Dried Linseed Oil - 


— 


26 


22 


268-8 


208-7 


100-3 



ADDENDA. 

Lithographic Printing Ink Delicate Tints, — ^Venice turpentine, 6 ; castor oil, 
16 ; white wax (bees or paraffin), 1 (all in lb.). Lemercier says Burgundy pitch 
is an essential ingredient, obviating great heat in boiling oil ; result is paler, keeps 
unctuous, is more pliable ; with moderate pressure the ink easily quits the stone 
for the paper, often entirely, but the greasy spots are inked again in due course. 

Lithographic Crayons, — (a) Wax, 2; (6) tallow, IJ; (c) white soap, 6J; 
(d) shellac, 3; {e) lamp-black, 1} (all in lb.). Melt (a) and (6), add (c) graduaUy, 
sturing constantly. Heat till mass fumes, take ofE fire, enflame for one minute 
at most, add («) stirring, put on fire again, boil J hour still stirring, cool slightly, 
run on a soap-smeared sheet of paper and mould into sticks. 



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CHAPTER V. 

RUBBEB SUBSTITUTES. 

India-Rubber Substitutes.^ 

Drying oils are used in the manufacture of solid elastic compounds 
which can be used as rubber substitutes. Sulphur, chloride of sulphur 
and nitric acid are the reagents used. 

Imitation rubbiars generally have drying oils as a basis, that is to 
say, linseed oil, walnut oil, etc. (this latter oil is too dear, and is only 
mentioned to show that the same results caij be got with it as with 
linseed oil). But non-drying oils are also extensively used, e,g,, colza 
oil in Germany and maize oil in America, in the making of chloro- 
sulphuretted oil substitutes from sulphur chloride. Receipts are 
innumerable ; each maker has his own sleight of hand ; practice and 
experience play an important part, and an irreproachable imitation 
is not made on the first attempt. Numerous experiments are neces- 
sary to arrive at the right proportions and the proper temperature. 
We do not intend to enumerate all the known and proposed receipts 
for making imitation rubber. Even if we knew them all, one scruple 
would prevent us ; generally the published receipts are obsolete, fit 
to guide the beginner in practical researches, but not sufficient for 
immediate and profitable use in trade. It will be sufficient, therefore, 
to dwell upon the origin of the two principal varieties of imitation 
rubbers, viz,y (1) oxidised oil and (2) vulcanised oil substitutes. 

(1) Oxidised Oil, Black Substitutes, — Sacc's Experiments on the 
Action of Nitric Acid on Linseed Oil, — Sacc, whilst studying in 1846 
the saponification of linseed oil by caustic soda, examined the action 
of nitric acid on that oil. When 100 parts of linseed oil and 200 parts 
of nitric acid, diluted with four times its volume of water, are gently 
heated with continual stirring, the oil wiU be seen to become of a 
brownish-red colour ; there is abundant disengagement of nitrous 
vapours, the oil thickens, and at the end of four hours the mass 
acquires a very decided syrupy consistency. 

Zonas' Method of Preparing " Caoutchouc des Huiles ". — L. Zonas, 
resuming in 1848 the experiments of Sacc, set fire to linseed oil 
previously viscous, then, after having partially burnt it, he treated 
the residue with dilute nitric acid. This was the beginning of 
oxidised oil rubber substitutes {caoutchouc des huiles). 

^ See also the writer's translation of India-rubber and Outta-percha (Scott, 
Greenwood & Co.). 

(72) 

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EUBBER SUBSTITUTES. 73 

Sollier and Battler's Attempts. — In 1854 F. Sollier, whether 
ignorant or not of these laboratory experiments, tried to prepare 
from linseed oil a product capable of replacing rubber in some of its 
essential applications. Eattier patented a similar product. Present 
Process. — A certain proportion of linseed oil is heated until it is con- 
verted into a brown viscous mass. To thus convert 10 kilogrammes 
(say 22 lb.) it is necessary to heat for at least twenty-four consecutive 
hours. The viscous mass is afterwards treated in the hot for a few 
hoiirs with nitric acid until it has assumed a thick plastic consistency, 
and when cooled in the air becomes solid. The product is freed from 
the excess of acid by kneading it for some time in a rather weak 
alkahne lye until it no longer has an acid reaction. In the cold it 
exhibits the appearance of natural rubber ; it is rather elastic, softens 
in hot water, and, unlike rubber, becomes plastic hke gutta-percha. 
It is soluble in spirits of turpentine, carbon disulphide and alkahes. 
Acids precipitate it unchanged from its alkaline solution. 

Although dilute nitric acid and linseed oil yield a product some- 
what analogous to the one next to be described, viz., that obtained 
by the action of chloride of sulphur on oils, yet in the latter case it 
would appear to be the sulphur which is the active agent, and which 
explains why we can have the same substance by using either drying 
or non-drying oils. In the present case, however, we are confronted 
with a. rapid oxidation process exclusively confined to those oxidisable 
principles only found in drying oils. The oil is first heated so far as 
to render it viscous ; it is then boiled for a long time with dilute 
nitric acid. A sohd elastic, brown substance, which does not stick 
to the fingers, is obtained analogous to caoutchouc, whence its name 
of black artificial rubber. The same substance is obtained with 
the different drying oils, but in proportion to the intensity of their 
drying properties. Linseed oil and walnut oil yield eight to ten 
times as much as poppy-seed oil. 

As soon as discovered the product was utilised for the manufac- 
ture of canvas, imitation leather for saddlery and carriage building, 
and travelling articles of a suppleness and fitness leaving nothing to 
be desired. Its use, although less and less considerable for some 
time back, is still in vogue, and if it be but rarely used alone it is still 
sometimes added to articles made from pure rubber. As it adheres 
perfectly to all fabrics without altering them or penetrating them too 
deeply the manufacturers of waterproof canvas often resort to it. It 
may also be applied without any difficulty to wood, to stone, and to 
metals, and in so doing it contracts a most remarkable adherence. 

Properties of Oxidised Oil Bubber Svhstitute. — This substance 
does not melt, but may be differentiated in a very precise manner 
from the final product yielded by the complete oxidation of drying 
oils, viz.y linoxin, by the fact that it cannot be saponified by a con- 
centrated aqioeous solution of potash. On heating, an emulsion is 
obtained which does not separate on the addition of an acid. With 
alcoholic potash, on the contrary, complete saponification takes place, 



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74 MANUFACTUBE OF VARNISHES. 

and the addition of an acid liberates a mixture of fatty acids of com- 
plex constitution. With carbon disulphide there is an emulsion ; in 
petroleum the substance swells without dissolving ; in a mixture of 
alcohol and ether it swells and dissolves if a large quantity of ether 
be added, whilst it is precipitated if alcohol be added in too great 
proportion ; finally, it is soluble in ether and in a large excess of 
spirits of turpentine. Eubber substitute, prepared from linseed oil 
and nitric acid, would appear to consist on the one hand of a mixture 
of substances present in the original oil and not sensibly changed by 
the nitric acid treatment, and on the other hand of products oxidised 
by the nitric acid and transformed into linoxin, the relative propor- 
tions of these substances masking the individual properties of each of 
them. 

This substance is used either in solution in ether or in spirits of 
turpentine in waterproofing fabrics, or is added directly in the solid 
state to india-rubber.^ 

(2) Vulcanised Oils. — Chloride of Sulphur Process^ White Substi- 
tutes. — By mixing Unseed oil with 5 per cent, of chloride of sulphur 
the oil becomes very thick, becoming plastic with 15 to 20 per cent., 
the solidity increasing as the percentage rises to 25 per cent. If the 
mixture be cooled solid sheets are obtained, on which other layers 
can be superimposed in such a manner as to obtain plates thick 
enough for making printing rolls, boxes, knife handles, etc. If a 
certain quantity of carbonate of lime be added the carbonic acid 
evolved converts the mixture into a white spongy mass, which is 
mixed with natural rubber. Chloride of sulphur has a similar action 
on other oils such as earthnut or colza. 

Nickles and Eochleder were the first to observe the action of 
chloride of sulphur on fatty oils, by which they are transformed into 
a substance rathier resembhng rubber. Mixed with any vegetable oil 
chloride of sulphur immediately converts that oil, almost at the 
ordinary temperature, into a solid substance possessing great hard- 
ness at times. 

Parkes' Patent. — Parkes, to whom industry owes the process of 
vulcanising rubber by chloride of sulphur, patented a process for 
vulcanising linseed and rape oils by means of chloride of sulphur 
(British Patent, 22nd October, 1855, No. 2359). 

Boussiris Researches. — In 1858 Eoussin communicated to the 
Academy of Science the result of his researches on the action of 
chloride of sulphur on oil (29th November). If we take 100 parts of 
Unseed oil and about 25 parts of chloride of sulphur a compound is 
obtained possessing the maximum of hardness, but 100 parts of linseed 
oil and 15 to 20 parts of chloride yield a more supple product ; and, 
finally, 100 parts of oil and 5 of chloride thicken the oil, it is true, but 
do not harden it. This latter combination is soluble in all ordinary 

^ Synthesis of Genuine Rubber, — The attempts that have been made to 
convert sphits of turpentine into real rubber have not as yet been cSirried out 
in practice. 



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EUBBEB SUBSTITUTES. 75 

oils, which i8 not the case with thicker combinations, which only 
swell in these vehicles. When a certain quantity of linseed oil is 
diluted with 30 to 40 times its weight of carbon disulphide, and if 
one-fourth of the weight of oil be replaced by the same quantity of 
chloride of sulphur, a product is obtained which remains liquid for a 
few days. If this solution be applied on glass, wood, etc., the carbon 
disulphide evaporates immediately, and a coat of varnish is soon 
obtained. Several precautions must be taken in order to produce 
mixtures of chloride of sulphur and oil possessing the properties just 
referred to. 

It is first of all necessary to select a chloride of sulphur con- 
taining the strongest possible proportion of sulphur. This product, 
which is liquid, is poured rapidly into the oil, and the mixture is 
agitated in order to obtain a uniform mass. Soon the oil heats, the 
reaction is finished, and the oil hardens or forms a soft compound, 
according to the proportions of chloride. It is essential to only 
operate on small quantities at a time, and to avoid such an elevation 
of temperature as would volatilise the chloride, produce bubbles, and 
even blacken or carbonise the oil. Sulphur dichloride should never 
be used in preparations of this kind ; its action is too strong and too 
rapid; the oil being treated would carbonise very rapidly and the 
preparation would be irremediably burnt. When the two substances 
are intimately mixed the product is run on to a glass plate, or upon 
another plane polished surface, where it is equalised, then after the 
lapse of five to ten minutes, according to the temperature, whether 
greater or less, combination is complete. 

One hundred pounds of the oil are mixed with 4 gallons of benzo- 
line, and there is added a mixture of 25 lb. of sulphur chloride in 2 gal- 
lons of benzoline. The work should be done in a closed vessel provided 
with a stirrer, and the chloride of sulphur should be added only in 
small quantities at a time. Some heat is generated which causes the 
petroleum spirit to vaporise, while a little gentle heat at the end is 
sufl&cient to drive off the remainder. These chloride of sulphur sub- 
stitutes are generally of a pale yellowish colour, rather spongy in 
texture. They contain but little free oil, and no free sulphur. They 
work with the rubber better than do the oxidised substitutes previously 
described. 

As a final result a pellicle is obtained, which it is easy to raise ; 
all that is required is to detach one of the comers with the point of 
a knife and to pull the remainder gently by means of this comer. 
Moreover, several of these layers may be superimposed, taking care 
80 that they may amalgamate together well, to apply one above the 
other when the latter is cold. In order to ensure perfect amalgama- 
tion, moisture must be avoided, which decomposes the chloride and 
prevents adherence. 

By working as just described, solid plates are obtained capable of 
being used in making numerous articles which could only be done 
previously with rubber. These articles are perfectly transparent, 



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76 MANUFACTURE OF VARNISHES. 

provided care has been taken after making them to keep them in an 
oven, or in a hot chamber, for a sufficiently long time for the vapours 
disengaged by the chloride to escape. They resist atmospheric in- 
fluences, acids and weak alkalies ; but they are brittle, and emit a 
peculiar odour, from which it is difficult to free them. 

All vegetable oils may be used in the making of these substitutes, 
but linseed, rape-seed, earthnut and coLza oils are preferred. 

Brown Substitutes — Oils Vulcanised by Flowers of Sulphur. — 
Eubber substitutes made from chloride of sulphur, as we have just 
seen, are colourless, and in texture in no way resemble commercial 
rubber. Their manufacture is also dehcate, and liable to very fre- 
quent failures, due principally to the too energetic action of the 
chlorides upon the oils in presence of however slightly elevated a 
temperature. It has been found possible to overcome this difficulty 
,by the direct vulcanisation of linseed oil, by flowers of sulphur, which 
produces a black substance approaching more nearly to the natural 
colour of rubber, and which, by its slower and more gradual elabora- 
tion, avoids the innumerable accidents of a reaction accomplished too 
rapidly. This substitute, which at the present day has in the 
greatest number of instances displaced oil vulcanised by chloride of 
sulphur, is prepared as follows : Linseed oil previously heated to 
a temperature of 100° C. is intimately mixed with 5 to 10 per cent, 
of flowers of sulphur, according to the object desired, then heated 
gradually to a temperature of about 130° C. (266° F.). The mixture 
rapidly turns brown, and when it has got to the desired temperature 
and acquired a very pronounced syrupy consistency, it is left to itself, 
without, however, allowing the temperature to lower below 100° C. 
(212° F.). Vulcanisation is known to be finished by the deep brown, 
almost black, colour of the mass, and its ever-increasing thickness. 
At this point the process is conducted in the same way as in the case 
of chloride of sulphur substitutes. That is to say, the vessels are 
emptied on smooth, cold surfaces, so as to render the product de- 
tachable after complete cooHng. . One method of making substitutes 
from non-drying oils consists in taking 100 lb. of good Stettin colza oil 
and mixing it with 15 lb. flowers of sulphur, and heating the mixture 
with frequent stirring to a temperature of about 300° F. until a dark- 
coloured, almost solid, mass is obtained. On cooHng, the .substitute 
is of a rubber-like character, but devoid of the elasticity and tenacity 
characteristic of rubber. During the process, part of the sulphur 
enters into combination with the oil, part remains free. It is 
desirable that the free sulphur should be very small. The average 
amount is 2*5 per cent. ; when the amount reaches 5, it becomes 
objectionable, as it tends to produce defective goods. 

All the oil should be combined with the sulphur, as any free oil 
is found to act upon the real rubber with which the substitute is 
mixed, and causes it to decay. The fatty compound formed by the 
interaction of the oil and the sulphur is not soluble in petroleum ether 
^or petroleum spirit, but is acted on by alcoholic solutions of caustic soda. 



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RUBBER SUBSTITUTES. 77 

The substitutes of which we have just spoken are sometimes 
employed alone in the manufacture of waterproof cloth, water-pipes, 
etc., sometimes in combination with natural supple rubber for all 
other industrial uses. 

At the present day, therefore, it would appear that only one class 
of organic compounds plays an important rdle in the rubber industry, 
viz, J the products sold under the name of rubber substitutes, artificial 
rubber or imitation rubber, made by heating oils, whether drying or 
non-drying, with sulphur or chloride of sulphur, and the non-sulphur- 
etted substitutes made by oxidising linseed oil. 

Analysis, — Substitutes are generally met with in the form of yellow 

or brown elastic masses, without cohesion, breaking up under pressure, 

greasy and moist to the touch. Two of these substances gave the 

following results : — 

I. n. 

Water 1-00 0*86 

Sulphur 6-17 6*4 

Ash 6-62 0-8 

Substitutes in fact behave towards solvents like rubber itself ; in- 
soluble in alcohol, they only dissolve with difficulty and incompletely 
in benzol, carbon disulphide and spirits of turpentine, etc. To detect 
the presence of oils or fats in manufactured rubber, a method has been 
proposed which yields, in experienced hands, useful results. The 
rubber is digested in carbon disulphide to which 5 per cent, of spirits 
of turpentine has been added, the solution is filtered after a few hours, 
and distilled. A notable residue indicates the presence of foreign 
bodies of a fatty nature. The method has several drawbacks : first, 
vulcanised rubber is slightly soluble in the mixture of carbon di- 
sulphide and alcohol ; the experiment is not conclusive unless the 
fats are present in notable quantity ; finally, sulphur is likewise 
dissolved, and may give rise to error. In spite of these drawbacks, 
from a qualitative point of view, the method, applied with discre- 
tion, may jrield useful indications. For a quantitative estimation the 
process cannot be adopted, because the substitutes only dissolve 
partially, even when isolated and repeatedly digested in alcoholised 
carbon disulphide. The sorts examined, in dissolving, left a residue 
of 20 to 30 per cent, of their weight, and on each treatment afterwards 
still further lost 1 to 2 per cent., so that it cannot be admitted that 
the substitute is insoluble, and that it is the proportion of unchanged 
oil or fat which alone dissolves. Substitutes dissolve completely in 
petroleum at a high temperature, as vulcanised rubber does itself. 
Ligroin only dissolves them partially. Aqueous soda dissolves them 
with difficulty and incompletely. The action of alcoholic soda is dealt 
with further on. 

Hubl's iodine addition method seemed likely to 3aeld indications 
in its way, for rubber hardly absorbs iodine, whilst ttie sulphuretted 
oils should readily fix iodine, like the oxidised oils which almost re- 
tain their primitive iodine value. Preliminary experiment led to this 



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78 MANUFACTURE OF VARNISHES. 

unexpected result : sidphuretted oils do not absorb iodine and behave 
like quasi-saturated compounds, 

Henriques tried to separate the sulphur from the substitutes and 
to isolate and weigh the regenerated fatty acids. He treated the 
substitutes with alcoholic soda, to which different salts which ought 
to absorb sulphur were added — salts of lead, mercury, copper and 
zinc ; but in whatever way operated od, the fatty acids, isolated from 
the alcoholic lye in very variable quantity, always contained equally 
variable quantities of sulphur. He tried, without any better success, 
to effect saponification and desulphurisation in a closed vessel at a 
high temperature, by replacing ethylic alcohol by amylic alcohol. 
However, it was found by these experiments that substitutes dissolve 
freely and completely in alcoholic soda, and on this property may be 
based at least an approximate method of analysis. In this field 
sharp and complete separations such as can, for example, be done 
in inorganic analysis are quite impracticable. Results can only be 
approximate. We have in fact to deal not with simple combinations, 
but with very complex mixtures, like rubber itself, which may contain 
substances belonging to different classes of bodies. The following 
experiment shows that substitutes, or at least their organic con- 
stituents, are completely soluble in alcoholic soda. 

One gramme of substitute was boiled in a flask attached to a 
reflux condenser, with an excess of caustic soda (7 to 8 per cent. 
NagO). After a few hours the alcohol was distilled off, the residue 
dissolved in water, and filtered through a tared filter. 

Weight of the dry residue - - - 0*041 = 4*1 per cent. 
Weight of the ash - - - - 0-0413 

The residue, therefore, no longer contained any trace of organic 
matter. Another substitute which left no ash dissolved without 
residue. 

Both white and brown substitutes present themselves under the 
form of slight yellowish, clotted, elastic masses, with a neutral 
reaction and a slightly penetrating oleaginous odour. Water ex- 
tracts nothing ; acids and alkalies but little ; neither do the majority 
of neutral organic solvents. 

The characteristic of these products is their high percentage of 
chlorine, almost as high as their percentage of sulphur. According 
to the behaviour of the products with solvents, the chlorine should 
exist in organic combination. If, therefore, as all the facts lead us 
to suppose, and as the experiments which will be detailed further on 
show, the substitutes examined result from the action of chloride of 
sulphur upon oils, that reagent has entered entirely, chlorine and 
sulphur, into the molecule of the proximate constituents of the oil. 
In order to facilitate the explanation of the results, Henriques' 
analyses are given below. 



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RUBBER SUBSTITUTES. 



79 



I. ANALYSES OF COMMERCIAL RUBBER SUBSTITUTES. 





White Substitutes. 


Brown Substitutes. 


A. 


B. 


C. 


A. 


B. 


Stdphur in the substitute 

Chlorine in the substitute 

Water in the substitute . - - - 

Ash in the substitute .... 

Percentage of fatty acids 

Sulphur in the fatty acids 

Chlorine in the fatty acids 

Iodine value of the substitute - 

Iodine value of the fatty acids 


6-4 

5-0 

0-85 

0-8 

90-45 

6-12 

0-83 

30-9 

91-3 


6-17 

5-86 

1-0 

5-51 

73-58 

6-45 

0-43 

31-0 

91-2 


8-25 
8-88 

8-15 

32^6 
102-3 


15-48 
0-7 

14-14 

42 
129-0 


17-71 
0-36 

15^ 

42-0 
125-6 



II. ANALYSES OF SUBSTITUTES PREPARED WITH— 





A 

9-34 


B. 


C. 


D. 


E. 


F. 


G. 


H. 


I. 


Sulphur in the substitute 


4-78 


8-28 


6-59 


7-68 


_ 


4-82 


10-6 


6-23 


Chlorine in the substitute 


8-84 


4-85 


7-62 


5-95 


7-44 




6-70 


8-95 


5-36 


Water in the substitute - 


302 


0-85 


— 


— 


— 











Ash in the substitute 


0-0 


0-0 


00 


0-0 


0-0 


00 


0-0 


0-0 


0-0 


Percentage of fatty acids - 
Sulphur in these acids - 


79-6 


1-67 


86-89 


87-95 


74-90 


— 


85-35 







9-88 


4-06 


8-34 


6-54 


8-32 


— 


5-32 





6-44 


Chlorine in these acids - 


Traces. 


0-60 


Little. 


Little. 


— 


— 


0-26 


Traces. 


Traces. 


Iodine value of the sub- 




















stitute - 


56-3 


52-6 


32-5 


29-9 


33-6 


42-8 


85^2 


21-9 


30-8 


Iodine value of the acids 


160-3 


141-21 


101-5 


102-8 


133-3 


129-2 


136-28 


143-5 


91-5 


Acetyl value - 


21-0 


19-6 


31-0 


— 


— 


— 


— 


105-6 


51-3 



A, Raw linseed oil ^fresh). B, Oxidised oiL C, Rape oil (fresh). D, Oxi- 
dised rape oil. E, Oxidised poppy-seed oil. F, Mixture of oxidised linseed and 
poppy oils. G, Castor oil with a minimum dose of chloride of sulphur. H, 
Castor oil with a maximum dose of chloride of sulphur. I, the oil termed soluble 
c8usitor (oxidised cotton-seed oil). 

The determination of the sulphur of substitutes necessitates the 
same precautions as rubber. Oxidation by nitric acid, followed by 
fusion with an alkaline oxidising agent, alone yields concordant 
results. In order to estimate the chlorine, nitrate of silver was 
added to the nitric acid, so as to avoid all loss by volatilisation of 
the hydrochloric acid. After alkaline fusion, the whole is digested 
in water, the insoluble silver combinations are separated (generally 
metallic silver), and the sulphur is estimated in one portion of the 
liquid as sulphate of baryta, and the chlorine by titration with nitrate 
of silver and sulphocyanate. As already mentioned, oils solidified by 
chloride of sulphur only absorb insignificant quantities of iodine. 
Sample A, Table I, for example, gave an iodine value, according to 
Hiibl, of 7'2. However, this value is only apparent. The feeble 



1 Another determination gave iodine value = 121 -0. 
* Two other determinations gave 147 and 162'1. 



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80 MANUFACTUBE OF VARNISHES. 

iodine absorption is partly due to the fact that the product is almost 
insoluble in chloroform. By frequently agitating the finely divided 
substitute in suspension in that liquid with an e:&cess of iodine solu- 
tion, and leaving it in contact for twelve hours, Henriques obtained 
in the case of the sorts A and B, Table I., iodine values of 30'9 and 
31. Compared with the iodine values of the drying oils used to make 
these • substitutes, these figures are very low. Chloride of sulphur 
3eems to partially saturate the free valencies of the oil to as great 
an extent by its chlorine as by its sulphur, possibly by its chlorine 
alone. It is to be noted that substitutes treated with iodine, in 
chloroformic solution, strongly retain the metalloid, and it is neces- 
sary in the back titration by hyposulphite to insist on stirring energeti- 
cally and for a long time so as to destroy all the iodine in excess. 

It should be interesting to observe how substitutes behave on 
saponification. We already know that they are completely soluble in 
alcoholic soda. In this reaction, the chlorine is almost eliminated, 
whilst the percentage of sulphur in the fatty acids corresponds exactly 
with the percentage of sulphur in the substitute. However, the pro- 
portion of fatty acids found is always lower than simple saponification 
would imply, even taking into account the elimination of the chlorine. 
Thus, Sample A gave 90 per cent.. Sample B only 79*4 per cent, of 
fatty' acids. A portion of the oil and a corresponding quantity of 
sulphur must therefore have undergone a transformation of a different 
order. The liquid from the saponification contains much chlorine 
but no apparent sulphur nor sulphuric acid, sulphuretted hydrogen 
nor sulphurous acid. But on evaporating these liquids in presence 
of the excess of hydrochloric acid added to liberate the fatty acids to 
the point where hydrochloric acid fumes begin to be given off, the 
presence of much sulphuric acid is demonstrated. It would seem, 
therefore, that the chloride of sulphur, with the assistance of oxygen 
borrowed either from the air or the substitute itself, had transformed 
a portion of the oil into a sulpho-oleic acid analogous to those pro- 
duced in the manufacture of turkey-red oil. In all substitutes made 
by Henriques these sulpho-oleic acids were formed, in greater or 
less quantity, with a consequent diminution of substituted fatty acids. 
These concomitant reactions are difl&cult to regulate, for even when 
working under apparently identical conditions, he obtained variable 
proportions of insoluble fatty acids. As saponification eliminates 
chlorine from the molecule of the substitute, it was to be foreseen 
that the isolated acids would appreciably absorb more iodine than 
the substitutes from which they were derived, whilst the ordinary 
fatty acids yield, as is known, an iodine value approaching that of 
the oils from which they were derived. In fact, the iodine valites of 
the fatty acids are almost triple those of the substitutes. Little is 
known of the action of chloride of sulphur (SgClg) on fatty oils. 
Warren asserts that drying oils yield solid masses with chloride 
of sulphur, insoluble in carbon disulphide, whilst the non-drying 
oils yield products soluble in that solvent. Stolmann, in the last 



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RUBBER SUBSTITUTES. 



81 



(German) edition of Muspratt's Dictionary y writes that these results 
merit but little reliance, because it is known that olive oil — the type 
of the non-drying oils — is transformed by the action of chloride of 
sulphur into a mass analogous with rubber, insoluble in ether. The 
facts pointed out in Sommer's patent, as well as Henriques* results, 
formally contradict Warren's assertions. 

If a sufficient quantity of chloride of sulphur be added to a fatty 
oil, the two liquids soon mix. After a few moments of contact 
energetic reaction sets in, accompanied by considerable disengage- 
ment of heat. The mixture froths, rises, gives off vapours of chloride 
of sulphur, with a Httle hydrochloric acid, sulphurous gas, and after 
a few seconds becomes converted into a soHd, elastic, scarcely tacky 
mass, capable of being ground and crushed under the pestle. Ex- 
posed to the air, the mass loses the excess of chloride of sulphur 
employed and the adherent hydrochloric acid ; it then resembles in 
every respect the white rubber substitutes of commerce. If one or 
other of the reagents, or both, be diluted with a neutral solvent, 
carbon disulphide or benzol, the reaction is longer in being mani- 
fested, its violence is moderated, but the final result is the same. 
The substitute is a little more porous in consequence of the volatihsa- 
tion of the solvent. That is how the reaction goes on in presence of 
a sujQBcient quantity of chloride of sulphur. In the contrary case, 
along with a less disengagement of heat, a pasty, tacky residue is 
obtained, which even a long time afterwards, whether in the hot or 
in the cold, does not solidify. The quantity of chloride of sulphur 
required to transform an oil into a soHd substitute varies with the 
nature of the oil, according to Henriques' experiments. 



100 parts of 
oil of 



^ Linseed ^ 
Poppy 
Rape 
Cotton 
Olive 
Castor 



do not yield 
a solid pro- 
duct with 



Parts SoCL. 




Parts SnCL 


26 ^ 




f 30 


30 




36 


20 


but do so 


26 


40 


' well with " 


45 


20 




25 


18 




20 



It will be seen from the inspection of these figures that there is 
no relation between the drying properties of oils and their aptitude to 
solidify under the action of chloride of sulphur. Having thus fixed 
the required proportions of chloride of sulphur, Henriques prepared 
and analysed substitutes with a Hnseed oil, rape oil and a poppy oil 
base, and with a mixture of equal parts of Unseed oil and rape oil. 
The results are given in Table II., p. 79. Neither of these substitutes 
are analogous with the substitutes A and B of Table I., products of 
English origin, of which it would be desirable to know the method of 
preparation. On the contrary, the commercial sample C (Table II.) 
yielded, on analysis,. figures so similar to those of the rape oil sub- 
stitutes C, of Table I., that they may be rightly regarded as identical. 
The iodine values of the fatty acids isolated from substitutes present 
such wide differences from one kind to another that agreement in 
the iodine values may be taken as proof of identity. Moreover, 

6 

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82 MANUFACTURE OF VABNISHES. 

Henriques learned from a manufacturer that the btUk of the sub- 
stitutes made in Germany are made from rape oU. 

The distinctive characteristiG of the English substitutoB A and B 
is their relatively low percentage of sulphur, according to which only 
20 per cent, of chloride of sulphur had been used to soHdify the oil. 
With the exception of castor oil, only the oxidised oils can be 
sohdi£ed with that proportion of chloride of sulphur. 

Baw linseed oil, for example, which requires at least 30 parts of 
sulphur chloride, SgCU, to soUdify it when it is fresh, only requires 15 
to 18 per cent, when it has been heated for some hours at 200"" to 
260° C. (say 392° to 482° F.). If the temperature be pushed to 260° 
to 300° 0. (482° to 672° F.), 10 per cent, of SgCLj suffices. A substi- 
tute prepared in that way would run into 4*78 per cent, of sulphur 
and 4'85 per cent, of chlorine.* All drying oils behave in this respect 
like linseed oil. 

By pursuing this method, Henriques identified the English sub- 
stitutes with the product obtained by the action of chloride of sulphur 
on oxidised cotton-seed oil, known in the English trade under the 
name of soluble castor oil, " lardine ". 

Brown Substitutes, — These are met with in commerce sometimes 
in the form of deep brown, tacky blocks, sometimes in powder. 
Analysis shows the presence of a much greater quantity of sulphur 
than in the substitutes which we have previously examined. But 
chlorine is almost entirely absent. These substitutes are undoubtedly 
obtained by heating oil with sulphur. They also dissolve in alcoholic 
soda ; the soap, treated by an acid, disengages appreciable quantities 
of sulphuretted hydrogen ; the isolated fatty acids, however, contain 
a smaller proportion of sulphur than the substitutes from which they 
were derived. The iodine values of these substitutes and those of 
the fatty acids are rather high, from which Henriques concludes that 
it is linseed oil, or a mixture of linseed and rape oU, which is used in 
their manufacture. Henriques did not pursue the examination of 
these substitutes, which are much less interesting, from the scientific 
point of view, than those of which we have previously spoken. 

It was interesting to ascertain whether the vulcanisation of 
rubbers, sophisticated with substitutes, influenced the percentage of 
chlorine in the product. Henriques examined a number of manu- 
factured rubbers containing substitutes, and always detected chlorine 
in appreciable quantity. As no other chlorinated compounds are 
employed in the manufacture of rubber — with one exception, of 
which we shall speak later on — we may conclude that the presence of 
chlorine in the alkaline alcoholic extract of a rubber is due to the use 
of a white substitute. Quantitative tests, however, showed that the 
proportion of chlorine in manufactured rubbers is much less than that 
which corresponds with the quantity of substitute added. Thus, in 
two samples the percentage of substitute of which came out at 63 
and 12 per cent., Henriques only found 0*5 and 0*37 of chlorine, 
whilst calculating on an average of 7 per cent, chlorine in the sub- 



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EUBBEE SUBSTITUTES. 83 

stitute, Henriques ought to have found 3*7 and 0*9 per cent. CI. On 
vulcanisation, a portion of the chlorine is therefore disengaged either 
under the form of chloride of sulphur or as hydrochloric acid, or in 
some other way. 

If alcoholic soda extracts a notable quantity of substance from a 
sample of rubber, and the extract contains no chlorine, we have the 
means of deciding whether the rubber is mixed with brown substitute 
or contains a fatty body. We have seen that the fatty acids liberated 
from substitutes contain a rather smaller proportion of sulphur than 
the substitutes themselves. Those of brown substitutes generally 
contain more than 10 per cent. If, therefore, the fatty oils have not 
absorbed sulphur during vulcanisation — if they have not by the heating 
itself of the rubber been transformed into substitute — we should be 
able, by isolating the fatty acids from the treatment with alcoholic 
soda, and by estimating their percentage of sulphur, to distinguish 
between the addition of an oil heated with sulphur and an ordinary 
oil. In order to solve this point experimentally, Henriques heated 
rape oil with an excess of sulphur for several hours at a temperature 
of 130° to 136° C. (266° to 276° F.), the highest temperature reached 
in vulcanisation. Under these conditions, the oil dissolved large 
quantities of sulphur, which for the greater part recrystaUised out 
on cooling. After filtration the limpid oil was saponified, and the 
fatty acids separated in the usual way. Finally, the latter were 
dissolved in 90 per cent, alcohol to separate the precipitated sulphur, 
and the sulphur was estimated in the acids thus purified, in which 
were still deposited some crystals of sulphur after filtration. Found 
sulphur = 0'98 per cent. 

It will be seen that the quantity of sulphur found under these 
conditions may be neglected when compared with that which brown 
substitutes contain. The problem to detect in a rubber the presence 
of white substitute, brown substitute, or an ordinary fatty oil, and to 
estimate them therein, may therefore be regarded as solved. The 
presence of notable proportions of chlorine points to the addition of 
white substitute. The estimation of the sulphur in the fatty acids 
liberated from the alcohoHc soda extract decides between brown 
substitute and a fatty oil. The method is at fault if a rubber con- 
tains all these three categories of substance simultaneously, but 
evidently that occurs very rarely. 

Chemical constitution of white substitute (1) before, (2) after 
saponification : — 

(1) (2) 

x-GH-GHGl=y x-G = CH-y 

I I 

S2 S2 

x-CH = GHCl-y x-C=CH-y 



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CHAPTEE VI. 
THE MANUFAGTUBE OF DBIEBS. 

The principal substances used as " driers '* or aids in the process of 
oil-boiling are metallic lead (p. 33), oxides and salts of (1) lead and 

(2) manganese. 

Lead Compounds Used as Driers} — (1) Litharge ; (2) red lead ; 

(3) acetate or sugar of lead ; (4) lead borate ; (5) lead rosinate ; (6) 
lead linoleate. 

1. Litharge, PbO = 223; Pb = 92*83; = 717 per cent. Manu- 
factwre. — When metallic lead is heated in a current of air, it is oxidised 
into massicot, PbO. 207 parts of lead yield 223 of massicot. When 
this massicot is further heated, it fuses, and is known as litharge, 
or, from its scaly nature, as flake litharge. It does not, however, 
undergo any chemical change. When buying litharge for use as a 
drier, it should be guaranteed free from copper, which is often present 
in considerable quantity, and acts injuriously. Moreover it should 
not contain unconverted metallic lead. 

Properties. — Litharge should dissolve completely in dilute nitric 
acid and in acetic acid to a colourless solution. A green coloration 
would indicate copper. Any residue will consist, most probably, of 
grit ; acetic acid may leave a residue of non-oxidised blue lead. When 
litharge is heated with Unseed oil for some time at the temperature 
at which that oil is said to " boil," but, more properly, at which it 
undergoes destructive distillation, it dissolves in the oil. In varnish- 
making and oil-boihng it is often found at the close of the operation 
reduced to metaUic lead. In such cases very probably all its oxygen 
is seized hold of and absorbed by the ** boiling " oil. Litharge assists 
in oil-boiling in three different ways : (1) It may combine with any 
free linoleic acid in the oil at a comparatively low temperature to 
form linoleate of lead, which will dissolve in the oil as soon as it 
forms ; (2) at a higher temperature it will eliminate glycerine from 
the oil and combine with the liberated Hnoleic acid to form Hnoleate 
of lead, which wiU again dissolve in the oil as soon as formed ; (3) 
in the act of being reduced to metallic lead, it will part with its 
oxygen to the oil, and consequently by starting the oxidation process 
increase the drying properties of the oil. The drawback attendant 
on the use of litharge and all lead salts as driers is the dark colour 

^ Galen (131-200 a.d.) states that " white lead and litharge thicken and dry ". 
-De Meth, Med., iii., 4. 

(84) ^ , 

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THE MANUFACTURE OF DRIERS. 85 

which they impart to boiled oil, due no doubt to the dissolved lead 
linoleate. This dark colour is intensified by the great heat at which 
the oil must be kept for some considerable time before the litharge 
dissolves and plays its part. Another drawback attendant on the use 
of litharge and other lead salts is that the oil or varnish into which 
they enter cannot be used in conjunction with or in juxtaposition to 
pigments consisting of or containing sulphides liable to combine with 
lead compounds to form the black sulphide of lead. Sulphur emana- 
tions act similarly. Paintings or decorations injured in this way may, 
it is said, be revivified by washing with a weak solution of peroxide 
of hydrogen, which converts the black sulphide of lead into white 
sulphate of lead without materially affecting the painting in any other 
way. But this is erroneous. Thenard only used it to restore a white 
lead background in a black crayon drawing of Eaphael. Such colours 
as madder lake would be destroyed by hydrogen peroxide. This 
black coloration is very often due to the free sulphur contained in 
the pigment, and not to the combined sulphur, which, looked at from 
a rational point of view, must be regarded as more or less stable. 
But, on the other hand, linseed oil boiled over the naked fire with 
litharge gives an elastic, durable coat of greater lustre and less sus- 
ceptible to dry superficially than manganese boiled oil. In a word, 
litharge boiled oil is more of the nature of a varnish than manganese 
boiled oil. 

2. Bed Lead Minitm, PbgO^ = 685 ; Pb = 90*2 ; = 9*8 per cent. 
Manufacture. — Eed lead Pb304 is made by heating litharge in contact 
with air at 300° C, a temperature slightly below its point of fusion. 
The litharge should be free from copper. It gradually becomes con- 
verted into a fine red known as red lead. The manufacture of red 
lead is a Derbyshire industry, and the process of the present day 
differs in no essential particulars from that described so vividly by 
Bishop Watson 125 years ago. A variety of red lead, made by 
igniting white lead, is sold as orange lead. Although dearer in price 
it is no more efl&cacious as a drier than ordinary red lead. It always 
contains undecomposed carbonate. 

Composition, — The red leads of commerce differ in composition 
according to the length of time they have been fumaced. However, 
the proportion of oxygen absorbed by the litharge never exceeds that 
which corresponds to the formula 2PbO,Pb02 = PbgO^. When^red 
lead is heated it darkens, and then, at a temperature above 300° C, 
it gives 'Off oxygen, becoming reconverted into Htharge. Test for 
Pu/rity. — "When red lead is treated with nitric acid the two equi- 
valents of PbO are dissolved as nitrate of lead, leaving the PbOg 
behind as a puce-coloured residue which is perfectly insoluble in 
nitric acid, and only dissolves in dilute nitric acid after it has been 
reduced by the addition of oxaHc acid. When this reagent is intro- 
duced into the test tube, containing the nitric acid and red lead, 
vigorous action ensues, the whole of the puce-coloured oxide being 
converted into white crystalline nitrate, to which it is only necessary 



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86 MANUFACTURE OF VARNISHES. 

to add a little boiling water for complete and instantaneous solution. 
Any residue remaining is generally barytes. Sophistication with 
ground brick is only met with in books. Red lead, owing to its 
containing more oxygen perhaps in a more available state, may be 
regarded as a more energetic drier than litharge, and its function as & 
drier may be regarded as similar to what it plays in a storage battery. 

Other Uses, — ^Besides its use as a drier, red lead is used in the 
manufacture of wall paper, sealing wax, crystal glass ; mixed with 
white lead in oil it is used to form steam joints. Red lead ** sub- 
stitutes '* are of little or no use as driers. 

3. Lead Acetate (Neutral), Pb(C2H302)2 + SHgO. Sugar of 
Lead. Molecular Weight, 379. — This salt was formerly known as 
salt of Satv/m, or sugar of Saturn. It is prepared by neutralising 
acetic acid with litharge. It crystallises in oblique rhomboidal 
prisms, colourless, transparent and efflorescent. It is generally met 
with in the form of heavy compact crystalline masses, somewhat re- 
sembling loaf-sugar. Its odour is acetous, whilst its taste is both 
sweet and astringent, its after taste is bitter and disagreeable. It 
dissolves in \ part of cold water and in 8 parts of alcohol. Its 
solution slightly reddens blue litmus paper, and is partially decom- 
posed by carbonic acid, which at the same time liberates a small 
quantity of acetic acid, which preserves the rest of the salt from the 
action of carbonic acid. 

Action of Heat, — Crystallised acetate of lead melts at 75 '5** G., 
at 100° C. it loses water and a small quantity of acetic acid. It 
afterwards soUdifies, but towards 280° C. it again melts. The de- 
hydrated salt would appear to consist of a sesquibasic acetate. At 
higher temperatures it decomposes with disengagement of carbonic 
acid, acetic acid and acetone, leaving a residue of very finely divided 
and highly combustible metallic lead. Lead acetate is a very ener- 
getic drier ; perhaps much of the metallic lead found by varnish- 
makers at the bottom of their pots may come from the complete 
decomposition of the acetate and not from the litharge often used in 
conjunction with it. 

8a. Ba^ic Lead Acetate, — The so-called neutral lead acetate just 
described results from the combination of two equivalents, i.e., 120 
parts of monobasic acetic acid with one equivalent, i.e., 223 parts of 
the di-acid base litharge. When two equivalents of a monobasic acid 
combine with one equivalent of a di-acid base a neutral or normal salt 
is produced. But it is found in actual practice that certain neutral 
or normal salts, in their state of solution in water, can still dissolve 
and combine with a further proportion of base. Thus when one 
equivalent of neutral acetate of lead is dissolved in water, it com- 
bines on boiling with an additional equivalent of htharge to form 
the di-basio salt, PbA2Pb(HO)2. By digesting together one equivalent 
of sugar of lead with two equivalents of litharge the tribasic salt^ 
Pb(A)22Pb(HO)2, is produced. These basic acetates, owing to the 
fact that their excess of Htharge, or, rather, lead hydrate PbO,H20, 



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THE MANUFACTURE OF DRIERS. 87 

is in a loose state of combination, easily give up this excess to weak 
acids, even carbonic acid, as exemplified in the manufacture of white 
lead. Should a raw linseed oil contain free linoleic acid, agitation 
with a solution of basic acetate of lead wiU convert the former into 
linoleate of lead, and if the agitation be renewed from time to time 
this linoleate of lead will dissolve in the oil imparting drying pro- 
perties thereto, whilst the insoluble magma produced by the action of 
the basic acetate on the colouring matter and mucilage collects as an 
insoluble slime at the bottom of the vessel. Such is the principle of 
the refining of linseed oil by Liebig's method and the imparting of 
drying properties thereto in the cold by means of basic acetate of 
lead , a substance the utility of which is not appreciated either by the 
varnish-maker or colour-maker to the extent to which its intrinsic 
merits entitle it. 

4. Borate of Lead, Pb(B03)2 + HgO = SIO'S.— Borate of lead 
is a white substance made by precipitating the boracic acid in 382 
parts {i.e., one equivalent) of borax (NagB^Oy + 10 aq.) by one 
equivalent of a lead salt — that is to say, 331 parts of nitrate of lead 
Pb(N03)2 or 379 parts of neutral acetate of lead (PbCCgHgOg + 3 aq.). 
The mother liquor is filtered ofip, the precipitate is weU washed, filter- 
pressed and dried in the usual way. This substance combines the 
drying properties of both lead and boracic acid. It does not darken 
the oil to quite the same extent as other lead driers. 

5. Bosinate of Lead, — The first stage in the manufacture of rosinate 
of lead, erroneously termed resinate of lead, is the preparation of an 
alkaline solution of rosinate of soda. Eosin being an acid body of 
variable degrees of acidity, different samples require different pro- 
portions of caustic alkali for exact neutralisation. In actual practice 
the best plan is to add rosin gradually and with constant stirring to a 
very dilute boiling solution of caustic alkali of known strength until 
the latter is exactly neutralised. 100 lb. of rosin take about 22 lb. 
of 77 per cent, caustic. 

Starting from the data that every 62 parts of anhydrous sodium 
oxide (real alkah) present in solution as rosinate of soda require for 
complete precipitation one equivalent of a lead salt, viz., 379 parts 
lead acetate or 330 parts lead nitrate for complete precipitation, and 
knowing the original bulk of the alkaline solution used and its richness 
in real alkali, as determined by the hydrometer and the usual tables, it 
is easy to calculate the amount of lead salt necessary to displace the soda 
in the solution of alkaUne rosinate by lead, and thus throw down all the 
rosin as rosinate of lead. (See Saponification Value, pp. 114-117.) 

The dilute solution of the proper proportion of lead salt is 
gradually added with constant stirring to the equally dilute solution 
of alkaline rosinate ; the mother liquor is syphoned off, the precipitated , 
lead rosinate, which is further well washed, drained and dried. It 
may be heated to incipient fusion to expel water. 

6. Linoleate of Lead, — Linoleate of lead is made by precipitating a 
solution of linseed oil soft soap, made by saponifying Unseed oil with 



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88 MANUFACTURE OF VARNISHES. 

caustic potash in the usual way. 100 lb. of linseed oil on an average re- 
quire 19ilb. of pure caustic potash, equal to 16ilb. of anhydrous potassic 
oxide, for complete saponij&cation. (See Sap. Value, pp. 114-117.) 
Caustic potash is sold as containing so much per cent, of anhydrous 
caustic alkali ; when pure it contains 83*93 per cent. It is, therefore, 
a mere matter of calculation if 100 lb. of linseed oil require 19i lb. of 
caustic potash, when the strength is 83*93 per cent., to j&nd how 
much will be required for complete saponification when the strength 
is 80 (or any other figure) per cent. The soap is dissolved in five or 
six times its weight of water, and the Hnoleic acid precipitated there- 
from by a dilute solution of a lead salt. The exact proportion of lead 
salt for complete precipitation depends upon the amount and the 
strength of the caustic alkah used. 112'2 parts of pure caustic potash, 
equal to 94*2 parts of anhydrous potassic oxide, require one equivalent 
of a lead salt, say 379 parts lead acetate or 330 parts lead nitrate. The 
lead salt solution is added gradually to the soft soap solution with 
constant stirring. The mother Hquor is syphoned off the precipitated 
lead linoleate, which is then further washed, drained and dried. Heat 
after drying to incipient fusion to expel last traces of water. 

Manganese Driers. — The manganese compounds used as driers 
are : (1) Black oxide — MnOg ; (2) manganese sulphate — MnS04 ; 
(3) manganese acetate — Mn(C2H302)2 ; (4) manganese borate ; (6) 
manganese oxalate; (6) manganese linoleate ; (7) manganese rosinate. 
MetalHc manganese is a reddish-grey coloured brittle metal, diffi- 
cultly obtained from its naturally occurring oxides by heating strongly 
with charcoal. Finely divided metallic manganese has such aflSnity 
for oxygen that it decomposes water at the ordinary temperature, 
with evolution of hydrogen gas. In order to preserve it in an 
unoxidised condition it must be preserved in a hermetically sealed 
tube or under naphtha. This strong affinity of metallic manganese, 
as well as its compounds, for oxygen constitutes in great part the 
value of manganese ores for commercial purposes. This value is 
further greatly enhanced by the fact that the oxidised compounds 
of manganese, under certain circumstances, easily part with a portion 
of their oxygen, becoming converted into lower oxides, and these 
lower oxides, in contact with the air, reabsorb oxygen, and are re- 
converted into the original higher oxides. The drying properties 
which manganese oxides and salts impart to oils boiled in contact 
with them was said to be due to the fact of these oxides and salts 
being so easily deoxidised to a certain extent, and then just as easily 
reoxidised — e.g., 

3Mn02= MugO^H- Og, and again 
Mn304+ ©2= 3Mn02. 
But, as a matter of fact, linseed oil is not oxidised to any very 
great extent in oil-boiling. 

1. Black Oxide of Manganese Pyrolusite, MnOg = 87 ; Mn = 63*22 ; 
= 36*78 per cent. — This is the source from which the various 
salts of manganese are prepared. Not only is it the most im- 



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THE MANUFACTUEE OF DRIERS. 89 

portant, but also the most widely distributed of manganese minerals. 
It usually occurs in heavy compact masses, reniform, and some- 
times with a fibrous or radiated structure. The colour is iron 
black .to dark steel grey, and very often soils the fingers. It 
gives with unglazed porcelain a grey streak. The other manganese 
minerals give a brown streak. When heated alone it liberates con- 
siderable quantities of oxygen, and becomes converted into triman- 
ganic tetroxide, Mn304. Pure pyrolusite has a specific gravity of 4'9. 
In commerce pyrolusite is usually found as a coarse, dull, black 
powder, consisting of a mixture of manganese dioxide, sesquioxide 
and monoxide, and contaminated with the gangue, quartz, felspar, 
limestone, etc., which often amount to 40 or 60 per cent. Besides 
being used directly as a drier, pyrolusite — savon des verriers — is 
extensively used in glass manufacture to burn up any carbonaceous 
matter and at the same time impart a slight violet tint, which masks 
the usual yellow tint of glass. 

2. Sulphate of Manganese, MnS045H20 = 151 + 90 aq.— This 
beautiful rose-coloured salt is prepared on the large scale by heating 
pyrolusite with coal and dissolving the inipure monoxide, to which 
it has been reduced, in sulphuric acid. A little muriatic acid is added 
towards the end of the operation. The solution thus obtained is 
evaporated to dryness and afterwards exposed to a red heat, so as 
to decompose any sulphate of iron. The pure sulphate is filtered 
and drained from the insoluble oxide of iron. It crystallises with : 
7H2O below 6° C. ; 6H2O between T and 20° C. ; 3 to 4H2O at higher 
temperatures ; IH2O at 200° C. The monohydrated salt MnS04 
+ HgO = 169 is greyish-white in colour, and is the starting-point 
of the manufacture of all manganese driers. 

3. Manganese Acetate, — This salt is manufactured by double 
decomposition between acetate of lime and sulphate of manganese 
in equivalent proportions. 

The reaction is as follows : — 

Ca(A)a+ MnS04= CaS04 + Mn(A)2. 

Oalcimn acetate Manganese sulphate Calcium sulphate Manganese acetate. 

The brown acetate of lime may be used. A solution of acetate 
of manganese marking 22° Twaddell, specific gravity 1*110, is used 
in oil-boiling by steam in the proportion of 36 gallons to 10 tons of 
oil in conjunction with a small quantity of lead driers, the greater the 
proportion of which the darker is the resultant boiled oil. (See Vin- 
cent's process of oil-boiling by steam (p. 49), for which process this 
drier is especially applicable.) 

4. Manganese Borate, — This is prepared by precipitating a solution 
of 382 parts, i.e., one equivalent of borax, Na2B4O7l0 aq., with 169 
parts, i.e., one equivalent of the monohydrated sulphate of manganese, 
MnS04,H20. The sulphate of manganese should be free from iron 
and the borax from excess of alkaU. The iron may be removed by 
roasting the sulphate and redissolving. The excess of alkali may be 



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90 MANUFACTUBE OF VARNISHES. 

neutralised by the addition of the requisite quantity of boracic acid. 
Precipitation should be effected in the cold. This substance, when 
pure and skilfully prepared, is a perfectly white powder, but whiteness 
is not a guarantee of purity, as it is often most grossly sophisticated 
with sulphate of lime, zinc oxide, etc. 

It is sometimes very unskilfully prepared. Some commercial 
samples submitted to J. G. Mcintosh for analysis consisted of mere 
mechanical mixtures of sulphate of manganese and borax almost 
entirely destitute of drying power. 

Endemann and Paisley found the following percentages in four 
samples : — 

1. Borio acid, 89*36 ; manganous oxide, 12*00. 

2. „ „ 40*18; „ „ 16*19. 
8. „ „ 37*38; „ „ 31*06. 
4. „ „ 11*09; „ „ 6*43. 

This salt is also made by acting on borax with manganous chloride 
and is supposed to be represented by the formula MnB^O^, but the 
washing with water to get rid of the sodium chloride also formed 
partly decomposes it, and the salt is very apt to turn brown from 
oxidation. Many manufacturers use a large excess of borax, and 
simply drain the precipitate without washing it. In the above 
analyses No. 3 was a washed product which had been bleached with 
sulphate of sodium. No. 4 contained rosin. 

"When manganous sulphate is used in the manufacture of borate 
of manganese the yield is less than with the chloride, as the sodium 
sulphate dissolves quantities of the manganese borate. 

By reacting on manganous sulphate with the equivalent quantity of 
borax (see p. 89), Endemann and Paisley obtained precipitates which, 
in two cases, contained 2678 and 28*82 per cent, of manganous oxide 
and 42*36 and 39*69 per cent, of boric oxide (BgOg). If the salt were 
MnB^O^ the amounts of BgOg for these two percentages of manganese 
should be 52*8 and 66*8 per cent, respectively. Endemann and Paisley 
recommend the following process for the manufacture of borate of 
manganese: Manganous chloride is precipitated with borax mixed 
with enough caustic soda to double the amount of soda present. The 
precipitate is turbined, washed twice with a little water. The loss of 
boric acid is found by analysing the wash water, and is replaced by 
mixing solid boric acid with the nearly dry precipitate, and drying 
the mixture thoroughly. It may then be regarded as MnB^O^, with 
either three or five molecules of water. Borate of manganese pre- 
pared in this way gave capital results as a drier. 

5. Manganese Oxalate, — Manganese oxalate is made by precipi- 
tating a solution of oxalate of soda by a manganese salt. In boiling 
the oxalic acid of the manganese oxalate is decomposed with evolution 
of CO2, etc. Very energetic oxidising properties are claimed for the 
residual manganese. 

6. Manganese Linoleate, — Manganese linoleate is made in the 
same way as lead linoleate. A linseed oil soft soap is precipitated by 



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THE MANUFACTURE OF DRIERS. 91 

a solution of the monohydrated sulphate of manganese, 169 parts of 
which, or one equivalent, are equal to 112*2 parts, or two equivalents 
of pure oaustio potash which contain 83*3 parts of anhydrous potassic 
oxide (the percentage of real alkali contained in pure caustic potash), 
and as 100 parts of linseed oil require 19^ parts of pure caustic potash 
for complete saponification, it is easy to make the necessary cal- 
culation when working with potash of any strength different from 
the pure, viz,, 83*3 percent, of real alkali. Or potash lye of a certain 
gravity may he kept in stock, and its richness in real alkali ascer- 
tained from the customary tables and the gravity as indicated by the 
hydrometer. For lOQ lb. of linseed oil caustic potash equal to 
16^ lb. of real alkali must be used, starting initially with a weak 
solution and finishing with a more concentrated. The soft soap of 
commerce contains about 60 per cent, of water, and though often 
made from linseed oil is not invariably so, and, moreover, it is grossly 
adulterated with starch, silicate of soda, and so on. The varnish- 
maker who makes his own driers should, therefore, make also his 
own soft soap. 

Manganese linoleate is precipitated, washed, pressed and dried in 
the same way as lead linoleate. 

7. Bosinate of Manganese, — Eosinate of manganese is made in 
the same way as lead rosinate ; for every 80 parts of pure caustic- 
soda (containing 62 parts of pure anhydrous alkali sodium oxide) 
present in the solution of rosinate of soda, 169 parts of monohydrated 
sulphate of manganese are required for precipitation. 

Mixed rosinates of manganese and lead and mixed linoleates of 
manganese and lead, as well as mixed rosinates and linoleates of 
both lead and manganese, can easily be made in the wet way, e,g, : 
Saponify equal weights of rosin and linseed oil and precipitate by a 
solution of a mixture of the acetates or nitrates of manganese and 
lead in molecular proportions. Product in turps is a fine drier. 

Fused rosinates and linoleates are made by dissolving the oxides 
of lead and manganese in rosin or in hnseed oil respectively. The pro- 
portions may be calculated as follows : as the atomic weight of KHO 
66*1 is to the saponification value of the rosin or linseed oil, say, 
17*5 and 19*5 per cent, respectively, so is half the atomic weight of 
litharge 111*5 and manganese dioxide 43'5 to the amount of litharge 
or manganese required per cent. Commercial articles are often grossly 
adulterated. 

Besinates of Manganese and Lead, 

The true resinates of manganese and lead are made by saponifying 
such resins as copal by caustic soda and reprecipitating by a salt of 
lead or manganese. They form interesting compounds, but they are 
even more intractable as far as solution in oil is concerned than the 
original resins from which they are derived. 

Patent Driers : Concentrated Driers and Liquid Driers, — Con- 
centrated driers consist of the product obtained by heating linseed 



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92 MANUFACTURE OF VARNISHES. 

oil at 250° to 300° C. to the consistency of sticking plaster, with a 
quantity of litharge, red lead, borate of manganese greater than 10 
per cent, and even as high as 70 per cent, of the weight of the oil. 
Sugar of lead, oxide of zinc, etc., are added to or partially substituted 
for the preceding substances. 

Concentrated driers consist of a thick viscous mass, generally of 
a deep brown colour, composed essentially of fused linoleate of lead. 
A good product may be made by boiling in a small pot 7 parts (by 
weight) of good and aged Unseed oil — old tanked oil — with a mixture 
of 2 parts of litharge in powder and 2 parts of red lead. The oil at 
first assumes a beautiful red colour, which turns brownish as the 
temperature rises. Suddenly it thickens, looking like bronze in 
fusion, whilst at the same time abundant fumes are given off. A 
sample drop spotted on a glass plate should become in a minute 
perfectly solid, with no viscosity nor tackiness whatever. It is 
thinned down with spirits of turpentine or rectified naphtha to the 
requisite consistency when required for use. Concentrated driers dis- 
solved in benzol or spirits of turpentine are used to make " boiled '* 
oil or oil " boiled through the bung-hole '* in the cold from raw linseed 
oil. 

Terebine or liquid drier is made like concentrated driers, but when 
the pot is taken off the fire it is only allowed to cool for a few 
minutes, when it is thinned down with successive additions of spirits 
of turpentine, with constant stirring. It is then passed through 
coarse linen, and stored in closed vessels. Liquid driers consist 
therefore of linseed oil saponified and oxidised to a greater or less 
extent, i.e., heated until it will roll into pills, and afterwards dis- 
solved in spirits of turpentine. There are numerous recipes for 
making driers ; inter alia the following : — 

Concentrated Driers, 

7 lb. linseed oil. 7 lb. linseed oil. 7 lb. linseed oil. 

2 lb. litharge. 2 lb. sugar of lead. 1 lb. umber. 

2 lb. black oxide of man- 2 lb. red lead. 1 lb. litharge, 

ganese. 2 gallons spirits of tur- 1 lb. oxide of manganese. 

1 lb. red lead. pontine. 1 lb. sugar of lead. 

2 gallons spirits of tur- 2 gallons spirits of turpen- 
pentine. tine. 

Pale Liquid Driers — Terebines, 

7 lb. linseed oil. 7 lb. linseed oil. 7 lb. linseed oil. 

3 lb. pure dry white lead. 2 lb. borate of mangan- 2 lb. borate of manganese. 
1^ lb. sugar of lead. ese. 1^ lb. acetate of lead. 

2 gallons spirits of tur- 2 lb. zinc white. 2 gallons spirits of tur- 

pentine. 2 gallons spirits of tur- pentine. 

pentine. 

In the manufacture of white liquid driers the mass does not 
become red on boiling, but white at first, and afterwards a very 
faint yellow. Liquid driers are but little used for white colours 
— solid driers are preferred; but with other coloured paints very 
rapid drying is effected by simply adding, say, a few parts in 100 



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THE MANUFACTUEE OF DRIERS. 93 

of liquid driers to the raw oil used. Here we have a case of 
oxidation analogous to that pointed out by Chevreul, viz,, when a 
manganese-boiled oil is added to raw oil. Endeavours have been 
made by working in the cold to produce very pale liquid driers. 
One variety which is used very extensively is made by intimately 
mixing 100 parts (by weight) of finely pulverised sugar of lead 
with 1,200 parts (by weight) of poppy-seed oil. This mixture is 
exposed to sunlight in a glass vessel, and frequently stirred. There 
is got in this way a perfectly colourless oil, which, when thinned 
down with 260 parts (by weight) of spirits of turpentine, dries very 
rapidly, yielding a solid, durable coating. Hartley and Blenkinsop's 
drier consists of zinc oxide mixed with a solution of linoleate of 
manganese dissolved in naphtha. One per cent, of manganese 
Linoleate added to Unseed oil in a dilute naphtha solution renders it 
quick drying. There is no necessity to blow air through it. The 
air will do its work very well after the oil is applied to any given 
surface. 

The so-called " terebine " very often consists simply of japanners' 
gold size thinned down with spirits of turpentine. Japanners' gold 
size is linseed oil boiled with litharge, red lead, sugar of lead and 
zinc sulphate until it will roll into pills, and then dissolved in spirits 
of turpentine. Another process consists in fusing 2 parts of Manilla 
copal, which is then mixed with i part of linseed oil and 6 parts 
of concentrated driers made by one of the formulae given above, 
after which the whole is incorporated with 14 parts of spirits of 
turpentine. The bulk of the paste '* patent driers*' used in the 
trade consist of 90 per cent, or more of a mixture consisting of 
equal quantities of chalk and barytes and about 10 per cent, or less 
of actual driers. When it is desired to prevent the paint from 
cracking, very good results are obtained by using spirits of turpentine 
which has simply been shaken up with litharge and decanted. A 
liquid is thus obtained which does not affect the colour, and which 
also gives a very durable coating. 

Hannay's glyce lead linoleates and basic lead linoleates, made by 
dissolving about 2 parts (by weight) of litharge in 1 part of linseed 
oil at as low a temperature as practicable, should make excellent 
driers either per se or in turps or benzene. 



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CHAPTEE VII. 

THE DETECTION OP ADULTERATION IN LINSEED AND OTHER 
DRYING OILS BY CHEMICAL, PHYSICAL AND ORGANOLEPTIC 
METHODS. 

1. Smell, — It is almost impossible to add any oil to linseed oil 
whioh has got a pronounced odour without that odour being almost as 
pronounced in the raw oil as it is in the original adulterant. Eosin 
oil and fish oils make themselves felt in linseed oil by their charac- 
teristic odour. Fish oil is perhaps not so readily revealed by its 
smell in boiled oil, but it manifests itself even then when energetically 
rubbed between the palms of the hands, as if one were making a 
lather, and then applied to the nostrils. The characteristic smell of 
burning rosin is developed when the oil is burned, if it should contain 
either rosin or rosin oil. The smell of the pure genuine oil is very 
characteristic, especially when newly pressed ; it then has a bland, 
mucilaginous, appetising odour, but this odour gives place as the oil 
ages to a somewhat rank, but not unpleasant, though still charac- 
teristic smell. The newly pressed oil should not give off the smell of 
cooked turnips which have been overheated in the operation. That 
is a sign that the oil has been made from seed containing rape, or 
other cruciferous oils, and that it has been extracted at too great a 
steam heat. The nose is a very useful factor in the testing of oils, 
and no opportunity should be lost in training it and exercising it in 
its duties in this respect. But one must not be led away even by a 
smell into the fields of imagination ; one must not imagine himself 
in Dante's Inferno every time one smells sulphur. 

2. Taste. — The taste of linseed oil is also as characteristic as its 
smell ; when new it is bland and pleasant ; old oil is sHghtly acrid. 
Fish oils can hardly be detected in Hnseed oil by their taste unless 
present in large proportion, but the most minute trace of rosin oil 
can most easily be detected. When a linseed oil containing rosin oil 
first impinges on the palate nothing very much amies is discovered 
at first, and the operator thinks, as far as taste is concerned, the oil 
is all right, and perhaps if uninitiated goes away satisfied to perform 
some other test on the oil, but by-and-by a bitter, biting, acrid, 
nauseous taste makes itself felt on the back part of the palate, which, 
in pronounced cases, makes one shudder and expectorate to get quit 
of it. But it remains persistent for some considerable time. There 

(94) 

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THE DETECTION OF ADULTERATION. 95 

is no necessity to recall the taste of rosin oil, one remembers it all 
one's life. 

An abnormal uncommon smell in linseed oil is generally due, fish 
oil and rosin oil excepted, to some volatile oil or another. When 
water is distilled over Hnseed oil, or when linseed oil is treated with 
a current of steam, it should yield no other distillate than condensed 
water; a volatile distillate would point to spirits of turpentine or 
benzene. 

3. Colour of Baw Linseed Oil, — The colour of raw linseed oil is 
usually a brownish-yellow ; when refined it is almost colourless. A 
blue or green fluorescence exhibited when the oil is looked at on a 
black background with the back to the light is a sure sign of adultera- 
tion with either mineral or rosin oil. This bloom may be somewhat 
removed from the rosin oil by the addition of J lb. to 1 lb. of di-nitro- 
naphthalin to every 10 gallons of rosin oil, but the method is too 
costly ; besides the fluorescence has a tendency to return. Moreover, 
the nitro-naphthalin renders the oil acid, and, besides, it throws the 
rosin or mineral oil several shades back in darkness of colour. (See 
vol. ii.) 

The Golowr of " Boiled " Linseed OiL — This may vary from the 
pale colour of the raw oil itself to port wine or even porter colour, 
the latter colour being characteristic of oils from which the drier has 
not had time to settle out. Fluorescence or bloom should be care- 
fully looked for by spotting a drop of the oil on black paper, or on 
the black cover of a note- book, and turning the back to the Hght, 
lowering the paper to the knees, and gradually raising and lowering 
it at several inclinations. If any rosin oil or mineral oil be present 
it generally shows itself by the bloom manifested under these cir- 
cumstances. But the bloom is not so readily seen in boiled as in 
raw oil, especially when the rosin oil has been boiled along with the 
linseed. When the rosin oil is boiled along with the linseed, so long 
as not more than 2 or 3 per cent, of rosin oil is used, the practice is 
not quite so bad as at first sight might appear; the acidity of the 
rosin oil is corrected by the litharge, and the rosin acids are converted 
into rosinate of lead, and thus assist in stimulating the drying pro- 
pensities of the oil, and the profit on this small addition pays for the 
cost of boiling. The painter does not care to pay much higher for 
his boiled than he does for his raw oil, and to this extent he shows 
himself unreasonable. When the oil is full of flaky matter, and even 
after filtration continues to deposit foots, it points to cotton-seed oil 
having been boiled with the oiL Its stearine separates out ad infinitum, 

4. Specific Gravity, — The specific gravity of linseed oil at any given 
temperature is its weight compared with the weight of an equal bulk 
of water at the same temperature taken as unity. Sometimes, how- 
ever, the density at 100° C. (212° F.) is referred to water at 15° C, or 
60° F. (15*5° C), and so on. The reason of this is that the specific 
gravity bottle which is used to take the density of the oil is graduated 
at, say, 60° F. Moreover, the diflflculties in graduating a specific 



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96 



MANUFACTUBE OF VAENISHES. 



gravity bottle at 212° F. are sufficiently obvious. The specific gravity 
bottle may be had graduated to hold 1,000 grains at 60° F. or 50 
grammes or 100 grammes. When the bottle and stopper are tared 
in the case of the 1,000 grain bottle, the number of grains added to 
^ ^ restore equihbrium give directly the specific gravity of the oil, but 

in the case of the 50 grammes or 100 grammes 
the exact weight added to restore equihbrium 
has to be multiplied by 20 or by 10 respectively. 
For all practical purposes the density of linseed 
is taken with sufficient accuracy by the hydro- 
meter. The most useful hydrometer for linseed- 
oil testing is graduated from '900 to '950, and 
costs about fifteen to eighteen pence, and a 
suitable thermometer may be had for half a 
crown. The oil-refiner and boiler could not 
invest in two more serviceable instruments. 
Life is too short for taking the specific gravity 
of linseed oil by specific gravity bottles or 
Westphal balances. It is only wanted to the 
third decimal point, and that is given correctly 
by any accurate hydrometer. It will be seen 
that no two observers agree in regard to the 
gravity of linseed oil at any given temperature. 
Possibly some of these variations are due to 
experimental errors, but as a matter of fact 
it would be very difficult to get two samples 
of oils representing different bulks to coincide 
exactly in density, and not only in density, 
but in other particulars, and it may be advisable 
to discuss here, once for all, the reasons for 



y 


1 



Fig. 23.— Thermo- 
hydrometers for Oil. 







DENSITY OF LINSEED OIL.i 




09 






£ Density. 




<1>- 


Density. 


Observer. 


Observer. 


« 






& i 




12 


0-939 


Saussure 


15-5 9316-0-9345 


Lewkowitsch 


15 


0-932-0-937 


Allen 


17-5 ! 0-9305-0-9370 


Filsinger 


15 


0-9305-0-9352 


Wijs 


18 0-9299 


Stillwell 


15 


0-9325 


Souch^re 


18 1 9411 


^j 


15 


0-9347 


Schiebler 


20 0-9275-0-935 


Holde 


15 


0-9315-0-9345 


Thomson and Ballan- 


25 0-930 


Saussure 






tyne 


60 0-921 


n 


15 


0-9342 


De Negri and Fabris 


94 0-881 


It 


15-5 


0-931-0-937 


Mcllheny 


299 0-8809 


Allen 



1 Add or subtract 0-004 for every 10° F. above or below 60° F. 

2Wateratl5-5°C. = 1. 

Density of fatty acids of linseed oil — 

at 15-5° C. = 0-9233 (Allen). 

at 99° C. (water at 15° C. = 1) = 0*8612 (Allen). 

at 100° C. (water at 100° 0. = 1) = 0-8925 (Archbutt). 



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THE DETECTION OF ADULTERATION. 97 

this continual variation. The density of linseed oil, like all its other 
so-called chemical and physical "constants" (sic), varies (1) with 
the general purity and with the pedigree of the seed from which the 
plant which produced it sprung; (2) with the soil on which the 
plant producing the seed (which when crushed yielded the oil) grewf* 
(3) with the climate in which that soil was located; (4) with the 
manure applied to the crop ; (5) with the time of sowing ; (6) with 
the previous rotation of crops ; (7) with the season whether wet or 
^^y ; (9) with the after cultivation ; (9) with the time of harvesting, 
i.e., whether the seed was allowed to ripen too Httle or too much, i.e., 
whether or not the exact moment was seized for harvesting the crop, 
when the oil in the seed was in that state of maturity in which, after 
rational harvesting of the flax, threshing and storage, and winnowing 
of the seed and expression therefrom of the oil, the latter excels in all 
those good quahties for which linseed oil is so justly and so highly 
esteemed. Independently therefore of impure seed and adulteration 
of the oil, whether by intentionally crushing it with a greater or less 
amount of seed which is not linseed, or after expression by the 
addition of an oil previously expressed from seed which is not hnseed, 
or by the addition of marine animal oils (fish oil, whale oH, etc.), mineral 
oils or rosin oil, the density of genuine linseed oil, hke every other 
so-called chemical and physical constant, varies within rather wide 
limits. It is a very difficult matter indeed to convince the uninitiated 
that the properties of genuine linseed oil are not like the law of the 
Medes and Persians, ** which altereth not". But having gone into 
the reasons why raw linseed oil varies in composition and properties, 
it will only be necessary to refer to the matter again when it ia 
especially important to do so. 

Presuming, however, that we are dealing with a genuine oil, the 
density should never go below 0*931 nor above 0*934 in the case of 
raw hnseed oil. Books and trade journals give higher densities, but 
the oil is not to be met with on the market with a higher density- 
than 0*934; even 0*933 is rare. The Unseed-oil consumer is to a. 
great extent indebted to the farmer for the purity of the oil supplied, 
to him. The crusher must needs sell his oil-cake, and as, e.g., rape 
seed can be detected under the microscope and also by chemical 
means in the linseed cake, the crusher cannot very well crush a 
certain amount of non-drying oil with his linseed should it yield an 
oil of very high gravity. He can, of course, sophisticate it after- 
wards, but some crushers imagine that if they crush the two seeds 
together, and thus treat the oil exactly ahke, that the fraud will 
escape detection. So it may if the linseed oil from that particular 
batch of seed be of itself of high gravity and yield high tests generally. 
But then the crusher would be in hot water with the farmers and 
the agricultural societies to which they belong ; his oil-cake would get 
a bad name, and in the end the crusher would only prove once more 
that honesty is the best pohcy. 

Oils of Similar Gravity to Linseed Oil. — The only oils approaching 

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98 



MANUFACTURE OF VARNISHES. 



linseed oil in gravity are Lallemantia oil and certain fish or marine 
animal oils, which can be detected by methods given in the sequel. 

(His of Different Gravity to Linseed Oil. — All other vegetable 
drying and non-drying oils are specifically hghter than linseed oil, 
with the exception of wood oil, castor oU, croton oil, rosin oil, 
the hydrocarbide oil produced by the destructive distillation of rosin. 
When linseed oil is dear there might be a tendency to adulterate it 
with lower grade castor oil. The greater density, unless manipulated 
to meet the case by the addition, say, of rape oil, would at once 
indicate the sophistication, but here comes in the . bad effect of the 
high maximum densities given in books. Supposing 10 per cent, by 
volume of castor oil 0*960 gravity were added to a linseed oil of 0'931 
gravity. 

We get 9 X 0-931 = 8-379 
„ „ 1 X 0-960 = -960 

10 )9-339 
0-9339 

Now, as far as density is concerned, no one can go into a court of law 
— 'in face of what is given in books — and swear that the above sample 
is not genuine linseed oil. But happily every particle of the castor 
oil can be separated by alcohol and weighed. So the sophisticator 
has to bear in mind that his oil must not satisfy one test alone ; it 
must satisfy at least a score of tests. Eosin oil can be separated out 
from linseed oil almost as easily as castor oil ; when the soft soap 
made from a linseed oil containing rosin oil is dissolved in water and 
shaken up with ether the latter extracts all the rosin oil and floats 
to the top of the soap solution from which it is decanted, the ether 
distilled and the rosin oil weighed as described in the sequel (p. 112). 

TABLE SHOWING MONTHLY INCREASE IN DENSITY IN OILS EX- 
POSED TO AIR IN UNCORKED BOTTLES FROM ONE MONTH TO 
SIX MONTHS, THE BOTTLES BEING SHAKEN EVERY MORNING 
(THOMSON AND BALLANTYNE). 



Oil. 


Density, 
Original. 


Densities at end of each Month. 


1 


2 


3 


4 


5 


6 


Olive - 

Castor 

Colza - 

Cotton-seed 

Araohis 

Linseed 


0-9168 
0-9679 
0-9168 
0-9226 
0-9209 
0-9326 


0-9187 
0-9681 
0-9183 
0-9237 
0-9213 
0-9331 


0-9193 
0-9691 
0-9172 
0-9241 
0-9221 
0-9336 


0-9208 
0-9700 
0-9186 
0-9261 
0-9233 
0-9363 


0-9216 
0-9700 
0-9184 
0-9278 
0-9239 
0-9369 


0-9227 
0-9686 
0-9200 
0-9304 
0-9266 
0-9372 


0-9246 
0-9683 
0-9207 
0-9320 
0-9267 
0-9385 



5. Solidification Point of Linseed Oil — The temperature at which 
linseed oil concretes into a solid fat is a useful indication. But, 



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THE DETECTION OF ADULTERATION. 



99 



unfortunately, authorities dififer here as in every other physical or 
chemical " constant ". It is greatly to be feared that many of the 
determinations have not been made upon pure samples of linseed oil. 
It serves no good purpose to make elaborate preparations and pre- 
cautions to secure accurate results with the samples tested if they be 
impure or even contain a notable proportion of fatty acid. Before 
taldng the solidifying point intended to form a standard for future 
reference and comparison, the oil in question should be pure and the 
fatty acids ehminated by treatment with alcohol, and all trace of the 
latter got rid of by gentle heating. Linseed, walnut and hemp-seed 
oils would appear to have much the same freezing-point, viz., - 27° C. 
( - 17° F.), whereas cotton-seed 
oil has a freezing-point, viz,, - 2° 
C, very nearly that of water. 
But it must not be taken for 
granted that the freezing-points 
of mixtures of two or more oils 
can be calculated from the freez- 
ing-points of their ingredient 
oils. This would be a great 
mistake, and there is abundant 
evidence to show that mixtures 
of oils behave in this respect 
as abnormally as similar mix- 
tures in the inorganic world, 
and just as mixtures of the 
carbonates of potash and soda 
melt at a temperature much 
lower than either carbonate does 
alone, so also does a mixture of 
cotton-seed oil stearic acid and 
stearic acid from tallow melt at 
a temperature below that of 
either of these varieties of stearic 
acid. Again Jean was baffled 
in his attempt to determine the 
melting-point of oils Hke Unseed 
by mixing them with a known percentage of palmitic acid of known 
melting-point, but possibly he might have succeeded better had he 
used ceresin of high melting-point. 

The melting-point of the fatty acids from linseed oil, viz., 11° C, 
differentiates it from several other oils, especially cotton-seed oil, whose 
fatty acids solidify at -|- 28*5° to 30° C. But here, again, the utility 
of such data is negatived by the fact that, judging from analogy, the 
fatty acids from a mixture of the two oils in equal proportions would 
not be at all likely to yield a product with a freezing-point which 
would be the arithmetical mean of those of its constituents. Much 
information may be intuitively gained in regard to the solidification 




Fio. 24. — Apparatus for Determining 
Solidifying Point of Linseed Oil. 



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100 



MANUFACTURE OF VARNISHES. 



and melting-point of oils by observing the behaviour of the stock 
bottles and samples, filed away for reference, when a frost begins to 
set in, and again when the corresponding thaw ensues. Cotton-seed, 
olive, lard and colza oils are all solid long before linseed oil, and the 
latter ** thaws " much sooner than any of the others. The solidifica- 
tion point is more useful in identifying individual oils than in detecting 
sophistication. However, it may be laid down as a general rule that 
the freezing-point of drying oils is much lower than non-drying oils, 
and although fish oils in many of their properties resemble drying oils 
yet in this respect they show a marked difference, the freezing-points 
of most fish oils being about 0° C, whereas linseed oil is — 27° C. 

SOLIDIFICATION POINT OF OILS. 



OU. 



Sperm 
Olive - 
Whale 
Cod-liver - 
Neatsfoot - 
Trotter 
Lard - 
Arachis 
Cotton-seed 
Rape - 
Sesame 
Oleic Acid - 
Colza - 
Hazel>nut • 
Sunflower - 
Grape-seed - 
Black Mustard 
Beech-nut - 
Castor 
Poppy-seed- 
Camelina - 
Apricot 
Almond 
Hemp-seed- 
Linseed 
Walnut 
Pine - 
White Mustard 



Massie. 



Degrees C. 

+ 2-6 






+ 2 

- 3-76 

- 5 

- 6to7 

- 6 
-10 
-16 

- lto2 
-17 
-18 
-18 
-18 
-20 
-26 
-16 

-16 to 20 
-27 



Braconnot. 



(;. 



+ 8 

+ 7 



- 6 
-10 



-17 

-18 
-18 

- 2-6? 
-16 

-27-6 



Chateau. 



Fr. Chatin. 



Degrees C. 
- 2-6 



8-8 



- 6-8 

-18-6 



17-6 
-17-6 
-17-6 
-18-6 

-18-8 

- 2-3? 

-27-6 
-27-6 



Degrees C, 
+ 2-76 



3 
8-76 



6-25 



-17-5 
-18 
-18 
-18 



-27-6 
-28 



Various. 



Degrees C. 

+ 2 + 6 
10+1+2 

1-0 

1-6 

1-6 

- 7 

- 3 
-3-26- 



- 6-76 
-20 

-16 




-21-22 
-10-12 
-26-7 



80 
-17-6 



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THE DETECTION OF ADULTERA'TJ'Ql!?. : :;;-o . ^^J^Ol 
SOLIDIFICATION POINT OF LINSEED OIL AND ITS FATTY ACIDS. 





J r\T^ 


Fatty Acids. 


Linseeu v/u. 


Solidification Point. 


Melting Point. 


Degrees C. 


Observer. 


Degrees C. 


Observer. 


Degrees C. 


Observer. 


-16 after 1 
standing j- 
several days J 
-27 
Melts at ) 
-16 to 20/ 


Gusserow. 
CMteau. 
Glaesner. 


13-3 
17-6 

16 to 17 1 

19 to 20-6 \ 
19 to 19-4 / 
20-2 to 20-6 


Von Huble. 

Allen. 
De Negri & 

Fabris. 

Holde. 
Lewkowitsoh 


17 

24 

Below 13 

20 to 21 1 


Von Huble. 

Allen. 

Dieterich. 

De Negri & 

Fabris. 



6. Colour Tests for Linseed Oil. 

A. The Sulphuric Acid Spot Test for Linseed Oil. — This is un- 
doubtedly the most valuable qualitative test for the purity of linseed 
and other oils. Yet it is conspicuous by its absence from most 
technical works on oils or is disposed of by a few words in passing. 
The apparatus required is simple : (1) Three or four glass rods rounded 
or dubbed ; (2) a stoppered bottle containing concentrated sulphuric 
acid ; (3) a white porcelain slab with several circular hollow depres- 
sions as shown in the illustration, or a plain porcelain slab will do, or 
even a plate of glass with a sheet of white paper underneath, but for 
the sake of cleanliness and accuracy the circular depression plate is 
much to be preferred as the oils have a tendency to run into one 
another and it is difficult to avoid getting into a nasty mess when 
testing a series of oils. The circular depression for each oil avoids 
all this unpleasantness. Eubber bulb tubes are also used for spot- 
ting acid. 

Process, — Put a number on each sample bottle of oil to correspond 
with the number of the depression on the plate. Then spot ten drops 
of each oil to be tested from its bottle on to its corresponding de- 
pression on the plate. Then dip one of the glass rods, which must 
be scrupulously clean, into the sulphuric acid bottle and carefully 
carry away on it as much as will spot one drop of acid, being careful 
not to drop the superfluous acid about the table. Two drops are 
generally necessary, one above the other. Care has to be taken to 
place the rod in a beaker when done with. It must not be allowed 
to touch the oil. If it be desired to stir the oil another rod must be 
used. The two drops may often be spotted at once from the acid 
secured on the rod by one dip, but it is best to be content with one 
drop and to make a second dip into the bottle for the second drop. 
The rod must be allowed to drain, but not too much. If a Mohr's 



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rl©^! .••••:: : -m'^^^facture of varnishes. 

burette with a glass stop-cock is available, the sulphuric acid can be 
spotted from it with greater ease and cleanliness. 

Pure linseed oil under the sulphuric acid spot test behaves as 
follows : — 

The spot quickly assumes a yellowish tint, passing quickly to 
orange, then to bright red, darkening gradually to brownish black. 

The oils which may be detected in linseed oil by the sulphuric 
acid spot test are : — 

(1). Bosin Oil. — Should the linseed oil contain as little as 6 per 
cent, only of rosin oil the behaviour of the sample will show a marked 
deviation from the pure sample. It becomes brownish red instantly 
pjid passes much more quickly to black than the pure sample, and 
the black coloration is always deeper than that of the pure oil. 





oooo 
oooo 
oooo 



IG. 25. — Apparatus for Detecting Rosin Oil in Linseed (Sulphuric Acid Spot Test). 



Even smaller quantities than 5 per cent; of rosin oil can be detected 
by this means. If the smell, the taste, the gravity and the sulphuric 
acid spot test all point to the presence of rosin oil, it should now be 
determined by Allen's saponification and ether extraction method (see 
p. 112), and very possibly it will be the only adulterant present. 

(2). Whale Oil. — As soon as the centre of a spot of pure whale oil 
is touched by the sulphuric acid a rapid motion takes place from the 
centre to the circumference, chasing, so to speak, a grey coloration in 
front of it. The central spot, at first red, passes to brown red, and, 
in a quarter of an hour's time, the whole of the spot becomes a 
brownish black. In testing linseed oil for whale or other oils in this 
way it is better to simultaneously test a standard sample of genuine 
linseed oil, a standard sample of genuine whale or other oil along 
with the oil to be tested, examining and comparing the effects. 



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THE DETECTION OF ADULTERATION. 103 

(3). Cod Oil, — The moment the drop of acid touches the oil red- 
violet strias appear in the centre, which afterwards turn to dirty red 
and finally to black. The centre of the spot is dark yellow, passing 
to bright brown, the contour of the spot of oil is hardly altered. 
Another description says the effect of the acid is to give an orange 
spot with a dark nucleus giving birth to a purplish floating crust 
which quickly browns. Stirring gives a bluish purple, turning to red 
and finally to brown. 

(4). Skate-Liver Oil (Density 0*928 at 15° C.).— Sulphuric acid 
spotted in the centre causes beautiful violet striae to swim about, 
which suddenly pass to bright brown. The centre of the spot is red, 
covered with brown striae. A dirty grey aureole surrounds the cir- 
cumference of the spot. Gaseous chlorine does not darken the colour 
of this oil even after half an hour's contact. 

(6). Bape Oil, — Before stirring gives a greenish-blue aureole. 
After stirring a bluish-green. 

(6). Hemp-seed Oil. — The reagent gives a yellow spot where the 
acid has been dropped, the remainder of the oil turns greenish blue^ 
then a beautiful emerald green, with small brown striae on the edges* 

(7). Bavison Oil. — This oil is known by its sharp pepper-Hke taste. 
The. reagent gives a bluish-green aureole, which soon passes to dirty 
grey, leaving on the edges dark brown spots. The centre instantly 
becomes reddish yellow, turning to bright brown. 

(8). Sesame. — Is the only oil which gives a characteristic bright 
red. 

(9). Poppy. — Gives a yellow immobile spot with orange rings. 
Turns buff on stirring, and finally brown red with disengagement of 
gas. 

(10). Walnut Oil. — Yellow spot, which moves from one side to 
the other, arid gives birth to quite an orange pellicle on the surface of 
the oil ; stirring produces dark streaks and hberates bubbles of gas. 

(11). Mustard Oil. — According to Lefevre, gives a dark yellow 
spot with fibrous streaks, inclining to orange, and a nucleus which 
rapidly darkens. On stirring it gives a red-brown colour. On the 
other hand, according to Heydenreich, black mustard oil behaves 
somewhat like rape, giving a greenish blue both before and after 
stirring. 

B. Tetrabromide of Tin Test for Bosin Oil. — Tetrabromide of tin, 
SnBr^ (made by dropping dry bromine through a separating fimnel 
into a well-cooled glass flask containing granulated tin), gives a 
characteristic violet-red coloration in presence of rosin oil. It is, 
perhaps, equally dehcate and characteristic a test for rosin oil in 
linseed oil as the sulphuric acid spot test. This test is due to Allen, 
and is a modification of Eenard's stannic chloride SnCl^ test. 

C. The Liehermann-Storch Acetic Anhydride and Sulphuric Acid 
Coloration Test for Bosin Oil. — Storch has adapted Liebermann's 
colour test for rosin acids for the detection of rosin oil in linseed and 
other oils. From 1 to 2 c.c. of the oil to be tested are agitated with 



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104 



MANUFACTURE OF VARNISHES. 



1 o.c. of aoetic anhydride with the aid of a gentle heat. After settling 
and cooling the acetic anhydride is drawn off by a pipette and one 
drop of concentrated sulphuric acid added. A fine but fugitive violet 
coloration is imparted to the acetic anhydride if rosin oil be present 
in the oil tested. This test is especially applicable for testing mix- 
tures of rosin oil and mineral oil. Morawski obtained the undernoted 
colorations with the following oils : — 



ou. 


Coloration. 


Oil. 


Coloration. 


Olive - 


Light Green. 


Palm - 


Brownish Yellow. 


Sesame 


Greenish Blue Gradual. 


Bone Fat 




Hemp - 


Green. 


Acids - 


Brownish Yellow. 


Linseed 


Green. 


Whale 




Cotton 


Green. 


Stearine - 


Brownish Yellow. 


Arachis 


Red Brown. 


Olein - 


Brownish Yellow. 


Rape - 


Greenish Yellow. 


Crude Olive 


Light Brown to Dark 


Castor 


Yellowish. 


Acids 


Green. 


Cocoa-nut - 


Yellowish. 


Herring 


Cherry Red to Brownish 


Palm-nut - 


Yellowish. 




Black. 


Beef Tallow 


YeUowish. 


Sunflower - 


Blue Violet to Blue. 



These colorations do not as a rule interfere with the detection of 
rosin oil. 



7. Flash Point of Linseed Oil, Gray's Apparatus (Closed Test). 



Description. — This apparatus (Fig. 26) consists of a brass oil-cup, 
a, of the same dimensions as the oil container used in Government 
Standard Petroleum Testers (Abel's) . On this cup, which is set on a 
suitable stand, is placed a tight-fitting cap or lid. Through the lid a 
steel shaft passes, carrying on the top a small bevelled wheel, h^ the 
bevel of which is milled, and on the lower part two sets of stirrers, one 
of which is below the surface of the oil, and the other in the vapour 
space above. A horizontal shaft carried on two standards terminates 
at one end in a bevelled wheel, g, which gears with the wheel h, and . 
at the other end in a disc, c, the outer rim of which is made of bone 
or other suitable non-conductor of heat, and on this disc is fixed a 
handle, 6, for rotating the shaft. This horizontal shaft carries a collar, 
«, from which there projects two small pins at diametrically opposite 
points. By sliding the shaft slightly to the right the bevelled wheels 
are drawn out of gear, and the pins projecting from the collar put in 
position for actuating the testing arrangement. On the lid proper 
there are three orifices, one immediately in front of the test-light, d, 
and the other two at either side of it. Above the lid is the sliding 
cover, s, in which there are two orifices corresponding to those on 
the fixed lid. When the bevelled wheels are in gear the sliding cover 



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THE DETECTION OF ADULTERATION. 



105 



is held in its normal position by the spring at p, and the orifices in the 
fixed lid are covered. When the sliding cover is moved by bringing 
the pin e in contact with the pin p and turning the disc, c, about a 
quarter of a turn round, the orifices in it coincide with those on the 
fixed lid, and at the same time the test-light is depressed and brought 
into position for producing the flash when the proper temperature 
has been reached. 

In places where gas is not available, a good substitute to use for 
the test-flame may be obtained by passing a current of air or hydrogen 
through cotton-wool or other convenient medium saturated with gaso- 
line or other light hydrocarbon spirit. 




Fig. 26. 



Fig. 27. 



Fig. 26. — Gray's Flash Point Apparatus for Linseed, etc.. Oils (Closed Test). 
Fig. 27. — Apparatus for Determining Flash Point of Linseed Oil (Open Test). 



Process, — Fill the oil-cup, a, up to the mark inside with the oil to 
be tested, replace the cap, and insert the thermometer in the tube pro- 
vided for it. Apply a light to the heating lamp, the heat from which 
may be applied either direct or through the medium of a convenient sand 
bath. Light the test- jet also, and adjust flame to about ^ of an inch 



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106 



MANUFACTUBE OF VAENISHES. 



in length. During the heating of the oil the stirrers should be moved 
at short intervals by turning the handle, b, several times. The more 
rapidly the oil is heated the oftener the stirrers should be rotated. 
When nearing the point at which the oil is expected to flash, it is 
advisable to reduce the rate of heating in order that the observations 
may be more readily and accurately made. If necessary, a rough 
test may be performed first, to give some indication of the tempera- 
ture at which the oil is hkely to flash. Observations may be taken 
every degree or half degree, a few turns of the stirrer being given 
between each test. The rate of heating is immaterial provided it is 
not too rapid to allow of readings being taken. A convenient time is 
ten to twenty minutes. 

8. Index OF Eefbaction. 

The index of refraction has not been much used as a means of 
identification or for detection of sophistication in oils. The following 
results are given for the purpose of comparing that of linseed oil with 
other oils : — 

Index of Befraction of Linseed Oil : — 

At 16° C. 1-4835 to 1-4855 (Strohme). 
At 60° C. 1-4660 (Thomer). 

Index of Befraction of Fatty Acids of Linseed Oil : — 
At 60° C. 1-4646 (Thorner). 



Index 


OP Refraction of Certain Oils. 




Index determined at 15°, correction 0*00037 at 15° C. 




Earth-nut, refined 


1-47325 


Trotter - - - - 


1-47045 


„ crude 


1-47315 


Horse-foot - - - 


1-47096 


Olive, Tunis 


1-47215 


Castor - - - - 


1-47990 


„ Kabylie - 


1-47015 


Almond, sweet 


1-47410 


„ edible 


1-47130 


Cotton - - - - 


1-47440 


„ fine - 


147070 


Black Mustard - 


1-47490 


Walnut 


1-47160 


Tjard (oil) - - - 
Oleic acid (sap.) - 


1 47195 


Poppy 


1-47730 


1-46246 


Sesame, crude - 


1-47490 


Whale (St. Vincent) - 


1-47505 


„ refined - 


1-47400 


»>---- 


1-47926 


Linseed - - - 


1-48140 


Cod-liver, Hogg - 


1-48600 


Neatsfoot - - - 


1-47550 


„ blonde - 


1-48836 



The following are indices of refraction at 15° C. of linseed oil, 
and of substances which may be present in it as adulterants or other- 
wise : — 



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THE DETECTION OF ADtTLTERATION. 



107 



ou. 


Refractive 
Index. 


Oil. 


Refractive 
Index. 


LinBeed - - - 
Cotton-seed 
HoflinoU - 
Mineral - - - 
Fish .... 


1-484.1-488 

1-476 

1-636-1-649 

1-438-1-607 

1-480 


Turpentine ... 
Rosin (Colophony) 
Maize- ... 


1-464-1-474 

1-648 

1-4766 

1-478 (at 20*^ C.) 



REFRACTION OF PURE AND IMPURE DRYING, ETC., OILS 
WITH JEAN'S REFRACTOMETER. 

Raw linseed oil — Laboratory standard sample - - +63° 

Refined raw linseed +49® 

Raw linseed + 20 per cent, rosin oil - • - - +67° 

„ +20 „ hemp-seed oil - - - + 47° 

„ +20 „ mineral oil - - - - + 17° 

Poppy ((BiUette) oil +29° 

old +86° 

Poppy ipavot) Calcutta oil + 27-6° 

» M » old + 83° 

Hemp-seed oil + 30° to 32° 

Walnut „ +86° 

Ravison „ +26° 

Colza „ - - - - + 17° to 18° 

Rosin 1 „ +78° 



REFRACTION OF PURE AND IMPURE LINSEED OIL WITH 
HEFELMANN'S REFRACTOMETER. 

Refractometer Nomber 
at 200" C. 

Pure Linseed Oil (raw) 80-5 to 82-2 

(boiled) - 80-5 to 84-2 

Linseed Oil + 20 per cent, rosin above 100*0 

+ 10 „ „ ..... 94-6 

+ 6 „ „ 88-4 

„ +20 „ rosin oil above 100*0 

„ boiled + 20 per cent, rosin oil - - - above 100-0 

,. +10 „ „ ... 92-7 

,, + 6 „ „ ... 88-2 

„ „ + 16 „ cotton-seed oil - - 78-7 

„ „ + 16 ,, rape oil ... 79*1 

„ +10 per cent, mineral oil - - - - 89*6 

„ boiled + about 30 per cent, of manganese 

rosinate 84*9 



' With some samples the whole field of the refractometer is black. 



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108 



MANUFACTUBE OF VABNISHES. 





§1 


1 a 1 






»^ .a h 


^ 


If 


« s s s s s s s^,©-** t z t t z >, 


o 


II 


o S o^ ^ 


^ 


'3 ffl 


^ 








Hi 


ill 


0> '^*»t-OiiH©1'^i«8oO<NCOU5«CO «0 


s 


s 1 issssssSssisss s; 

iH iH iH rH iH iH iH 00 fH iH iH iH iH iH rH 


S3 


r« 






Pk 

Q 
2; 


II 


1 

OiHO»O«fH'^i«t-00Sc0C0t-'^rHa0 S«0 
rHiHiHrHiHiHiHiHiH©iHiHiHiHiHiH 


J3 


"g 


1-3 




s 


«< 






o 


, 




i-i 


§ 


1 1 ■*" + 


1 

•s 


f.......,,,oLf,.......S 


I 


C8 

2 




3 


■go 


oi 9 9 


Q 


iH<NiHOOO>«OOOiOiSoOCOCOOio8 8 


CO 


1^ 


s 1 - 


^ 






3 




1— < 


Q 




.f4 

o 


» 




1 • 1 • • • • • q 1 • • • • • • 1 


hI 






3 




2 


(£) 




i 1 i 1 i • I I ^ 1 i 1 1 • 1 1 1 

o 


(^ 




P4 


tf 




••»••••• CO ••••• I • I 


p 




^ 


Ph 




.« 9 


S 




r-1 <N CO '^ »0 :g CDt-OOOJ^ ^ 


M 








1 1 11 1 i 

8. S §8. § '3 


Pk 







Therefore, if a sample of raw or boiled linseed oil, examined at 
26° C, is found to give a refractometer number greater than 84*5, it 
is open to the suspicion of containing an admixture of rosin, rosin oil, 
metallic rosinates, or mineral oil. On the other hand, if the refrac- 
tion falls below 80, then additions of slightly or non-drying fatty oils 
must be looked for. Very small percentages are not detected by the 
refractometer, but such are not likely to occur in practice. 

The above table shows in how far the refractometer test coincides 
with the results of chemical analysis. All oils exhibiting normal re- 

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THE DETECTION OF ADULTERATION. 



109 



fractions were found pure, and those refracting abnormally adulterated. 
The foregoing were purchased as pure boiled oil, with the exception 
of the last, containing 20 per cent, of rosin, which was prepared in 
the laboratory. Out of fifteen commercial samples, nine were pure 
and six contained rosin oil, the only adulterant detected. 

A slight turbidity on the addition of water to the saponified oil 
(p. 112) indicates the presence of small admixtures of rosin or metallic 
rosinates. (The production of a dark, flocculent, heavy precipitate in 
the case of manganese boiled oil should be disregarded as common to 
all boiled oil of this class. It cannot, therefore, be considered as 
indicative of the presence of rosin oil or mineral oil.) The polarisa- 
tion test gives either neutral or slightly dextro results, and both 
saponification and iodine numbers fall within the ordinary limits, so 
that no differentiation between slight quantities of added rosin or 
metallic rosinates is possible. The saponification test is reliable in 
presence of rosin oil or compounds of rosin acid with metallic oxides 
and mineral oils, but isuncertain when rosin is present. 

9, POLARIMETRIO TbSTS, 

The investigations of Bishop and Peters on the opticity of a 
number of oils show that, with the exception of castor oil, croton 
oil and rosin oil, the only dextro rotations are produced by sesame 
(high) and olive oil (feeble), all the others, including linseed oil, 
being either optically inactive or having a slight levo rotatory power. 

TABLE SHOWING THE ACTION OF OILS ON POLARISED LIGHT. 



Oil. 



Saccharimetrical 
Degrees (Peters). 



Saccharimetrical 
Degrees (Bishop). 



Almond (sweet) 
Beech-nut 
Castor 

Colza (European) 
„ (Japanese) 
Cotton-seed 
Croton 
Earth-nut 
Hazel-nut 
Hemp-seed 
Linseed - 
Olive 



Poppy-seed 
Sesame - 

(warm) 



Walnut 



(Indian) 



- 0° 2" 
Inactive. 
+ 40° 7" 

- 0° 1" 
+42° 6" 

+ 0°6" 
-0°2" 
-0°6" 
-0°8" 
+ 0°76" 
+ 1°3" 
+0° 76" 
+ 6°0" 



- 0° T' 



-2°1" 
- 1° 6" 



-0°4" 



-0°3" 
+ 0° 6" 



+ 8°!" 
+ 7° 2" 
+ 4° 7" 
+ 8° 9" 
+ 9°0" 
+ 7° 9" 
-0°8" 



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110 MANUFACTURE OF VARNISHES. 

(1). The Polarimetric Exarmnation of Linseed Oil Sophisticated 
with Befined Bosin Oil {BJi,0.), — According to Aignan such a mixture 
rotates the plane of polarisation to the right by an angle perceptibly 
proportional to the quantity of rosin oil which it contains. If the 
rotation observed with a 200 miUimetre tube be represented by [a]D 
and the weight of the rosin oil in 100 parts by weight of the mixture 
by h, we get in the case of a mixture of linseed oil with — 

1. Eefined rosin oil [a]D = + ^h. 

2. Choice white rosin oil [a]D = + ^| h. 

3. Eectified rosin oil [a]D = + fi h. 

The first mixture is the most common. In actual practice, there- 
fore, all that has to be done is to measure [a]D by the polarimeter, 
and to estimate h as refined rosin oil, according to the formula 
h = [a]D YT • The oils in question being dark in colour, it is better 
to work in a 100 millimetre tube and to calculate 

h = [a]D = V-. 

(2). Estimation of Bosin Oil in Paint by' the Polarimeter, — A. A 
certain amount of the paint is frequently stirred and shaken up with 
ether and allowed to settle. The ether containing the oil in solution 
floats to the surface and the polarisation tube is filled with the ethereal 
solution. If no optical deviation be produced, there is no rosin oil in 
the paint tested. On the other hand, if [a]D be the rotation towards 
the right with a 200 millimetre tube, according to Aignan's researches 
on the rotatory power of an ethereal solution of linseed oil contain- 
ing rosin oil, the proportion of rosin oil may be calculated by the 
formula — 

h-^m 

B. A known weight p^ of the ethereal solution is run into a flask 
and heated on the water bath at 100° C. (212° F.) so as to drive off 
the ether; the oil which boils only at 300° C. (572° F.) is left 
in the flask. Let its weight be represented by p^. The proportion 

^ 100 = h^ per cent, of oil (Hnseed oil and rosin oil) contained in 

P' 

the ethereal solution examined by the polarimeter. If h^ = h, it 

may be taken for granted that the paint contained linseed oil free 

from rosin oil. Generally, y is greater than h, then ^-,100 will give 

h 

the percentage of rosin oil contained in the Hnseed oil which was 

used to make the paint. 

10. The Percentage of Spirits of Turpentine and other Volatile 

Oils, Benzene and other Solvents, etc,-, — Spirits of turpentine, coal tar, 

naphtha (benzol and its homologues), shale naphtha and petroleum 

naphtha (shale spirit deodorised [sic\ petroleum spirit, etc.) are 



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THE DETECTION OF ADULTEEATION. Ill 

readily detected in linseed oil, whether raw or boiled, and whether 
they be present in comparatively small or relatively large proportions, 
by their characteristic smells, which are accentuated by placing the oil 
in a test tube or other vessel so as to half fill it, and then dipping the 
tube into boiling water after having corked it up. On releasing and 
removing the cork the characteristic odour of the individual volatile 
solvent present will make itself felt. 

Moreover, the greatly diminished flash point will also show sub- 
stances of this nature, and also the gravity if present in any quantity. 
To estimate the volatile oil quantitatively about 300 grammes are 
heated by a bath of molten parafl&n wax or by an air bath to about 
130° C. in a flask capable of being connected with a vessel in which 
steam is generated. It therefore has a cork fitted with an inlet tube 
reaching nearly to the bottom of the vessel, a thermometer inserted 
into the oil, and a tube for leading the steam and the vapour of spirits 
of turpentine, etc., which it carries in its train to a Liebig's condenser. 
The distillate will consist of two layers, an upper one of spirits of 
turpentine, etc., floating on a layer of water. The former may be 
separated from the latter by a separating funnel, and weighed or 
measured. The layer of condensed water retains traces of the 
volatile oil, but so small as may very well be neglected. Mcllheny 
found it to be about i of 1 per cent. 

Petroleum naphtha may be separated from spirits of turpentine 
by treating the mixture with fuming nitric acid. Petroleum naphtha 
remains unattacked, but spirits of turpentine is converted into sub- 
stances which can be dissolved in water, and thus eliminated from 
the mixture, leaving a residue of more or less pure petroleum naphtha. 
A measured amount of the distillate is run into 300 c.c. of fuming nitric 
acid (very slowly drop by drop) contained in a 750 c.c. flask attached 
to a reflux condenser. As each drop of the oil falls on the fuming 
acid a very violent reaction ensues, and the flask should be immersed 
in cold water to keep it cool, and it should be agitated from time to 
time. When the whole of the volatile oil to be treated has been 
added the flask is allowed to stand until all action has ceased, when 
its contents are run into a separating funnel (Fig. 28) and repeatedly 
washed with hot water, which eliminates the products produced by the 
interaction of the spirits of turpentine and the fuming nitric acid, 
such products being soluble in water. The residual petroleum oil is 
now measured and brought to per cent, by volume of the distillate and 
then to per cent, of the original oil. However applicable this method 
may be to petroleum naphthas consisting of pure paraffinoid hydro- 
carbides, it is on the face of it wholly inapplicable to inter alia shale 
naphtha, largely consisting of members of the ethylenic series of 
hydrocarbides, the so-called '' olefins *\ This is a point which seems 
to have been unaccountably overlooked by those writers who recog- 
nise and quote the above method as an efficient one for separating 
mineral naphtha from spirits of turpentine. 



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112 



MANUFACTUBE OF VARNISHES. 



11. Determination of Rosin Oil and Mineral Oil in Linseed OU hy^ 
Saponification and their Extraction from the Solution of the Resultant 
Soap by Ether, — Five grammes of the sample to be tested are saponi- 
fied with 25 c.c. of alcoholic potash, 80 grammes of caustic potash to 
the litre, in a capacious porcelain basin, care being taken to apply heat 
very cautiously at first, as the mixture froths much and is apt to take 
fire. When frothing has ceased a greater heat may be applied, but 
in bringing the soap to dryness at the end care must be taken ta 
avoid charring or overheating which might distil off some of the rosin, 
etc., oil. The operation may be done very well on the sand bath by the 
exercise of care. It is advisable to have a clean iron or copper plate 

to place on the top of the porcelain 
basin to extinguish the flame should 
its contents catch fire. The re- 
sultant soap is dissolved in the 
basin in 50 c.c. of boiling water 
and transferred to a separating 
funnel of about 200 c.c. capacity^ 
using about 20 to 30 c.c. of water for 
rinsing out the basin. (See p. 109.) 
After cooling 50 c.c. of ether are 
added and the solution and ether 
thoroughly shaken in the funneL 
The funnel and its contents are 
allowed to stand, when the ether 
separates out as an upper layer 
containing the greater portion of 
the rosin oil. A few drops of 
alcohol hasten the separation. The 
soap solution is then run off through 
the stop-cock whilst the ethereal 
solution is run into a flask. The 
soap solution is then retm*ned to 
the funnel and again agitated with 
ether and the process repeated until 
the soap solution cedes no more 
rosin, etc., oil to the ether. The 
ethereal solutions are united and washed with a small amount of water 
to eliminate any dissolved soap. The ether is then distilled off on the 
water bath and the residue dried and weighed. In a works labora- 
tory the greater part of the ether may be driven off by using several 
beakers of boiling water brought from the waste steam pipes, and if 
the laboratory lights are all out there is no danger of explosion. 
According to two French authors -^^ of the laboratory explosions 
are ether explosions. Ether vapour will explode or burn 12 feet 
away from its source, and the flame or explosion strike back to it. 
Glacial acetic dissolves mineral but not rosin oil. 

12. Estimation of the Free Acid in Linseed Oil, — Pure samples of 



Fio. 28. — Separating Funnel showing 
Separation of the Ethereal Solution 
of Rosin Oil from the Soap made 
from Linseed Oil containing Rosin 
Oil. 



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THE DETECTION OF ADULTEBATION. 113 

linseed oil, unless oxidised or thickened or very old, contain but 
small amounts of free fatty acid, whilst if sophisticated with rosin 
oil, which abounds in free rosin acids, the percentage acidity may be 
much increased. In the distillation of rosin there is a good deal 
of vesicular carrying over of unchanged rosin in the train of the 
vapour of rosin oil, hence the marked acidity of the latter. But the 
natural acidity of linseed oil increases greatly with age. So that 
although a high acidity might indicate the presence of rosin acids, 
and hence of rosin oil or free rosin, yet it would not be safe to come 
to a decided conclusion without confirmatory evidence. A portion of 
the acidity may even be due to free sulphuric acid used in refining 
the oil, but any appreciable proportion would point to unmitigated 
carelessness on the part of the refiner in washing, seeincj he hardly 
ever uses more than about 1 per cent, of acid. The actual amount 
of acidity due to sulphuric acid is estimated by repeatedly boiling a 
known quantity of the oil with water until free from acidity, collect- 
ing the wash waters, concentrating, and, after cooHng, adding neutral 
potassium iodide and iodate and titrating the liberated iodine, if any, 
with sodium h3^osulphite. The free iodine fouad is calculated to 
caustic potash, KHO, and deducted from the potash required to neu- 
tralise both the sulphuric acid and the organic acids present in the 
sample. The repaainder gives the free organic acids, which consist of 
the fatty acids from linseed oil alone if the sample be pure, but if 
adulterated it . may represent in addition the acidity due to the 
presence of rosin added either as such or in the form of rosin oil. 
The total free acid is determined as follows : From 5 to 10 grammes 
of the oil are weighed into a flask and 50 c.c. of alcohol added ; if 
methylated spirit be used it must be previously neutralised, as it is 
always acid. Heat to boiling on the water bath, shake and titrate 
with semi-normal alkali, and the result is calculated to milligrammes 
of caustic potash, KHO, per gramme of oil. 

The acidity of linseed oil expressed as oleic acid, according to Nord- 
linger, varies from 0'41 to 4*19. Mcllheny gives an acid value of 3'0 
as the usual figure, which equals oleic acid 1'51. A very old sample 
gave 7*1. Mills allows a maximum acid value of 10. It will be 
readily understood that boiled oil gives higher acid figures than raw 
oil. Weger allows as high an acidity as 12, and even in very much 
thickened oils he allows 30. Here, however, it may be noted that 
free rosin may be introduced by the addition of fused metallic rosi- 
nates, the so-called " resinates," with the accent on the e. The acid 
figure of boiled oil, says Mcllheny, is usually below 5, but it is more 
uncertain than the raw oil. A. figure above 10 is in his opinion un- 
doubtedly due to the presence of rosin, which seems rather a dogmatic 
dictum. The acid value of rosin varies from 145 to 180, and its 
detection is facilitated by its giving both a high bromine substitution 
figure as well as an addition figure. But the safest method is to 
estimate it quantitatively by one or other of the methods adopted in 
soap analysis, such as Gladding's or Twitchell's. But the process 

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114 MANUFACTURE OF VARNISHES. 

often recommended to exhaust the oil with pure alcohol and then to 
add an alcoholic solution of basic acetate of lead is not reliable, as 
linoleate of lead formed from the free linoleic acid does not dissolve in 
alcohol to any very appreciable extent more than the rosinate of lead. 
The operator is thus thrown back upon the character of the precipi- 
tate — always a very unreliable indication. 

It is quite unnecessary to give a table of acid values of linseed oil 
as they are of no use without the history of the samples to which they 
refer. 

13. Saponification Value of Linseed Oil, — This is defined as the 
number of milligrammes of caustic potash, KHO, required to com- 
pletely saponify 1 gramme (i,e,^ 1,000 milligrammes) of hnseed oil. 
Or, to use British units, it is the number of grains of caustic potash 
required to saponify 1,000 grains ; or, for that matter, the number of 
tons of caustic potash required to saponify 1,000 tons of oil. Divided 
by 10, the saponification value again gives the number of pounds of 
caustic potash required to saponify 100 lb. of oil. It is really a very 
simple matter, but the use of foreign, if scientific, units (grammes per 
litre when pounds per 100 gallons has the same meaning and effect) 
tends to render it unintelligible to the non-scientific layman. 

Beagents. — (1) Standardised hydrochloric acid, the strength of 
which is expressed in terms of caustic potash, KHO. The semi- 
normal acid is the most suitable ; such an acid contains in every litre, 
that is, in every 1,000 c.c, 18*25 grammes of anhydrous hydrochloric 
acid, HCl. The pure solution of hydrochloric acid is diluted by 
referring to the tables of density with distilled water until this 
strength is reached ; its exact strength is determined by estimating 
its chlorine as chloride of silver, AgCl. This solution may also be 
standardised by titration with a known weight of pure, dry, freshly 
ignited sodium carbonate, NagCOg, every 106 grammes of which are 
equal to 112*2 grammes of caustic potash, KHO. The hydrochloric 
acid, to be perfectly semi-normal, should be so diluted that 0*265 
grammes of pure anhydrous sodium carbonate require 10 c.c. of the 
diluted acid for neutrahsation. The exact strength of the standard 
hydrochloric must always be known in terms of caustic potash, which, 
when exactly semi-normal, is 1 c.c. = 0*02805 KHO. 

Alcoholic Potash Solution, — This need not be of a very exact pre- 
determined strength, but should approach, as far as practicable, the 
semi-normal, so that 1 c.c. of the alcoholic potash solution neutralises 
1 c.c. of the semi-normal acid. To 1 litre of alcohol 30 to 40 grammes 
of caustic potash are added, or rather 75 c.c. of an aqueous solution 
of caustic potash of 45** Baume or 90 c.c. of 36° Baume are run into 
a Utre of alcohol, and the whole allowed to stand and filtered through 
a ribbed filter, or decanted after clarifying into a bottle with a straight 
neck and corked with an indiarubber stopper, through a hole in which 
a 25 c.c. pipette passes, the end of which is closed by a piece of india- 
rubber tubing and a small cHp. It is not advisable to prepare too 
much of the solution as it is not stable. The alcohol should be the 



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THE DETECTION OF ADULTERATION. 



116 



purest obtainable, but if methylated spirit be alone available it should 
be purified by redistilling it over soap. The alcohol should not be- 
come brown, the colour of rum or cod oil in the process. A yellowish 
tint does not interfere with the titration. 

Process, — From 1*5 to 2 grammes of the filtered oil are weighed 
exactly into a 150 to 200 c.c. flask, then 25 c.c. of the alcoholic potash 
solution measured out by the pipette in the stopper of the bottle are 
added. It is not necessary to rigidly measure out 25 c.c. exactly, 
but precisely the same quantity must be taken for each experiment. 
After the contents of the pipette have drained it is better to grasp 
tightly the bulb of the pipette in the palm of the hand and " squeeze," 
as it were, the remainder of the liquid out of the pipette ; the heat 
of the hand expands the air inside the pipette, and the top aperture 
being closed by the finger, the expansion of the air causes all the 
liquid, except the merest traces, to be forced out of the mouth of the 
pipette. A similar flask with 25 c.c. of alcoholic potash is used as a 
blank experiment, and both are heated on the water bath simultane- 
ously for half an hour, care being taken to place a small watch glass 
or funnel on the mouth of each of the flasks. Two to three drops of 
phenol-phthalein are then added to each flask, and the contents 
titrated with the semi-normal hydrochloric acid. The difference 
between the blank flask and that containing the oil is calculated into 
potash ; the volumes of alkaline solution used being equal, the dif- 
ference is the potash used up by the oil. 1 c.c. of acid = 0*02805 
grammes of KHO, and this factor multiphed by the number of c.c, 
gives a number which, when reduced to 1 gramme of the oil, gives 
the number of milligrammes of caustic potash consumed by 1 gramme 
of oil, and this figure is generally called the Koettstorfer figure or 
saponification value. 

EQUIVALENT WEIGHTS OP CAUSTIC AND CARBONATED ALKALI. 



Potash Alkali. 



OaiBtic Potash - 
Anhydrous Potash 
Potassium Car- 
bonate 



1 


It 
1^ 


1. 

P 


KHO 


661 


112-2 


K^O 


94-2 


94-2 


K^COj 


188-2 


188-2 



Soda Alkali. 



Caustio Soda 
Anhydrous Soda - 
Sodium Carbonate 
Soda Crystals 





^f 


1.- 


Formula. 


It 
1^ 


1:^ 
1^ 


NaHO 


40 


80 


NajO 


62 


62 


NajCOj 


106 


106 


NajCO + lOaq 


286 


286 



The strength of commercial alkali is always expressed in per 
cent, of anhydrous alkali, as in the second horizontal line ; if the 
caustic potash be pure it contains 94 '2 per cent., and knowing the 
saponification value of the oil and the percentage of anhydrous potash 
in the alkali being used the calculation of the amount required to 
saponify any given oil or rosin whose saponification value is known 
is a simple matter. 



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116 



MANUFACTURE OF VARNISHES. 



Analytical Examples, — (1) Where the acid and alkali are both 
semi-normal, and (2) where neither are semi-normal. 

Example 1. — Linseed oil taken - - - 1*75 grammes. 

I Normal alcoholic potash taken - 25 c.c. 

i Normal acid used in back titration 13 c.c. 

12 c.c. 

Each c.c. normal acid = 002805 grammes KHO. 

12 „ „ =0-33660 

0-3366 grammes KHO = 336*6 milligrammes KHO. 

336-6 
^-P^ =192'4 milligrammes KHO. 

It therefore took 192-4 miUigrammes of caustic potash to completely 
saponify 1 gramme of the linseed oil in question. 

Example 2. — Benedikt and Ulzer give the following example : 
2-012 of oil were saponified with 25 c.c. of alcoholic potash and 9*65 
c.c. of standardised hydrochloric acid were used in back titration. 25 
c.c. of the alcohoUc potash = 22-5 c.c. of the standard hydrochloric 
acid. Again 1 c.c. of the standard hydrochloric acid = 0-0301 gramme 
caustic potash, KHO. There was used in saponification of the oil, 
therefore, an amount of caustic potash equal to 22*5 — 9*65 = 12*85 
c.c. of test acid, hence 12*85 x 0*0301 grammes = 386*8 milligrammes, 
for 2*012 grammes = 192*24 milligrammes for 1 gramme of oil. The 
oil tested therefore had the saponification value of 192*24. 

The saponification value of linseed oil is higher than that of most 
oils, but it can only be regarded as affording an indication of purity. 
Even a comparatively high saponification value is no guarantee that 
the oil is not adulterated with non-drjdng oils, which approach it very 
closely in this respect ; neither is it a guarantee that unsaponifiable 
substances, such as hydrocarbide oils, are absent. The only way to 
determine the absence or presence of these is to actually separate 
them out (and weigh them) by the saponification process first intro- 
duced by Thomson, and afterwards elaborated by Allen, which con- 
sists in first saponifying the oil and then extracting the hydrocarbide 
oils from the aqueous solution of the resultant soap by ether. (See 
Fig. 28, p. 112, and context.) 

SAPONIFICATION VALUE OF LINSEED OIL. 



Saponification 
Value. 


Observer. 


Saponification 
Value. 


Observer. 


Saponification 
Value. 


Observer. 


189-195 

195-2 

187-6 


Allen 

Moore 

Dietrich 


190-195 
190-192 

190-192-7 1 


Holde 
Thomer 
De Negris 
and Pabris 


187 

187-6 

192-4 


Mollhony 

Filsinger 



Saponification Value of Fatty Acids from Linseed Oil — ^198*8 (Dietrich). 

Digitized by VjOOQIC 



THE DETECTION OF ADULTERATION. 117 

When the saponification value is as low as from 180 to 185 then 
adulteration with rosin oil or mineral oil is to be strongly suspected, 
and when it falls lower than 175 their presence is certain (Weger). 
It may fairly be demanded of a raw oil that its figure shall not be 
lower than 187 and of a boiled oil not lower than 186 (Mcllheny). 
The high temperature used in the old-fashioned process of oil- boiling 
reduced the saponification value much greater than the much lower 
temperature now used with modern processes. The amount of metal 
introduced into the oil in the form of a metallic rosinate or Unoleate 
is so small as not to produce any very appreciable effect on the saponifi- 
cation value, and some of the boiled oils now in the market have 
almost as high a saponification value as that of the raw oil. 

14. Iodine and Bromine Value of Linseed Oil, — Linseed oil consists 
largely of unsaturated glycerides, the fatty acids of which combine by 
direct addition with 2, 4 or 6 atoms of bromine or iodine. Eosin, rosin 
oil and mineral oil do so only to a slight extent, and, menhaden oil 
excepted, no other adulterant to as great an extent as linseed oil itself. 
Direct halogen addition is not the only action ; there is another in 
which one-half of the halogen combines with the oil and the other 
half combines with hydrogen, which the first half of the halogen 
has displaced from the oil. The halogen has formed a substitution 
compound with the oil. If the hydrogen of glycerides can be but 
very sparingly replaced by bromine or iodine, it is not so with rosin, 
rosin oil and mineral oils. In fact though rosin and rosin oil absorb 
large amounts of bromine they do so by substitution and not by direct 
addition, and with American petroleum oils substitution compounds 
bulk largely in the absorption. 

The halogen absorption of oils is generally determined by Hiibrs 
method. It affords valuable data as to purity of any sample of 
linseed oil. But it does not differentiate between absorption by (1) 
addition and (2) substitution. It fails to discriminate between rosin 
and Unseed oil, the absorption figures of both linseed oil and rosin 
being somewhat close. 

Beagents — (1) Iodine Solution, — Dissolve 25 grammes of pure 
iodine in 500 c.c. of 95 per cent, alcohol. Dissolve 30 grammes of 
mercuric chloride in 500 c.c. of 95 per cent, alcohol. The last solution, 
if necessary, is filtered, and then the two solutions mixed. The mixed 
solution should be allowed to stand twelve hours before using. (2) 
Decinormal Hyposulphite of Sodium Solution, — Take 24*6 grammes 
of chemically pure hyposulphite of soda freshly pulverised as finely as 
possible and dried between filter or blotting paper. Make this up to 
1,000 c.c. at the temperature at which the titrations are to be made. 
(3) Starch Paste, — 1 gramme of starch boiled in 200 c.c. of distilled 
water for ten minutes and cooled to room temperature. (4) Solution 
of Iodide of Potassium, — 150 grammes of iodide of potassium dis- 
solved in water and made up to 1 litre. (5) Solution of Bichromate 
of Potassium, — Dissolve 3*874 grammes of chemically pure bichro- 
mate of potassium in distilled water, and make the volume up to 

Digitized by VjOOQIC 



118 MANUFACTURE OF VARNISHES. 

1 litre at the temperature at which the titrations are to be made. 
(6) Chloroform, — This should be pure and should not affect the titration 
results of the iodine solution after three hours' standing. 

Manipulation — Standardising the Hyposulphite of Sodium Solu- 
tion, — Eun 20 c.c. of the bichromate of potassium solution to which 
has been added 10 c.c. of the solution of iodide of potassium into a 
glass-stoppered flask. Add to this 5 c.c. of strong hydrochloric acid. 
Allow the solution of hyposulphite of sodium to flow slowly into the 
flask until the yellow colour of the Hquid has almost disappeared. 
Add a few drops of the starch paste and with constant shaking con- 
tinue to add the hyposulphite of sodium solution until the blue colour 
just disappears. The number of cubic centimetres of hyposulphite 
solution used multiplied by 5 is equivalent to 1 gramme of iodine. 
Example. — 20 c.c. KgCr.^Oj solution required 16*2 c.c. hyposulphite of 
soda ; then 16'2 x 5 = 81 = number of cubic centimetres of hypo- 
sulphite solution equivalent to 1 gramme of iodine. Then 1 c.c. hyposul- 
phite solution = 0'0124 gramme of iodine. Theory for decinormal 
solution of hyposulphite of sodium, 1 c.c. = 0*0127 gramme of iodine. 
Weighing the Sample, — About 0"15 to 0*18 gramme of oil is to be 
weighed in a glass- stoppered flask holding about 500 to 800 c.c. 
Absorption of Iodine, — The oil in the flask is dissolved in 10 c.C. of 
chloroform. After complete solution has taken place 30 c.c. of the 
iodine-mercuric chloride solution is added from a pipette. The chloro- 
form and iodine should give a clear solution ; if not, more of the former 
must be run in for that purpose, and 25 c.c. more iodine if the colour be 
discharged, as an excess is necessary. After two hours the deep brown 
colour must still be persistent. The flask is now placed in a dark place 
and allowed to stand, with occasional shaking, for another two hours. 
Titration of the Unabsorbed Iodine. — 300 to 500 c.c. of distilled water 
is added to the contents of the flask, together with 20 c.c. of the iodide 
of potassium solution. Any iodine which may be noticed upon the 
stopper of the flask should be washed back into the flask with the 
iodide of potassium solution. Any red precipitate of mercury iodide 
would indicate an insufficiency of potassium iodide which has to be 
remedied by adding more. The excess of iodine is now taken up 
with the hyposulphite of sodium solution, which is run in gradually, 
with constant shaking, until the yellow colour of the solution has 
almost disappeared. A few drops of starch paste are then added and 
the titration continued until the blue colour has entirely disappeared. 
Toward the end of the reaction the flask should be stoppered and 
violently shaken, so that any iodine remaining in solution in the 
chloroform may be taken up by the iodide of potassium solution in 
the water. A sufficient quantity of hyposulphite of sodium solution 
should be added to prevent a reappearance of any blue colour in the 
flask for five minutes. Control Experiments, — At the time of adding 
the iodine solution to the oil two blank flasks of the same size and 
nature as those used for the determination should be employed for 
conducting the operation described above without the presence of any 



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THE DETECTION OF ADULTERATION. 



119 



oil. The difiference between the mean of the results obtained by the 
blank experiments and that on the .oil corresponds to the iodine used, 
which is brought to per cent, of the oil. This figure gives the iodine 
value. The iodine value of boiled oil (see p. 108) often approaches 
that of the raw oil, especially those with a rosinate or linoleate drier. 

IODINE VALUE OF RAW LINSEED OIL. 



Iodine Value. 


Observer. 


Iodine Value. 


Observer. 


171-175 
170-181 
173-195 
171-190 


Lewkowitsch. 
Benedikt. 
Ulzer. 
Holde. 


173-6-187-7 
171-179 
176-3 1 
201-8 \ 


Thomson & Ballantyne. 
ShukofE. 

Wijs, by his Iodine 
Chloride Method. 



IODINE VALUE OF FATTY ACIDS OF RAW LINSEED OIL. 



Iodine Value. 


Observer. 


Iodine Value. 


Observer. 


178-5 
179-182 


Williams. 
Lewkowitsch. 


169-185 
179-192 


De Negri and Fabris. 
Holde. 



IODINE VALUE AND OTHER ** CONSTANTS" OF DIFFERENT BRANDS 
OF RAW LINSEED OIL.— (Lewkowitsch.) 





d 




PI 




4^ 
<x> a 










o 




f" O 


•rt 








■■s 


d 


Sa^ 


<1 


Linseed Oil from 


Sp. gr. at 
(Water at 
15-5° C.= 


1 


s 




■30. 

II 




Finest Calcutta Linseed, two months 














old 


0-9316 


1-3 


193-2 


170-46 


0-6 


0-65 


Finest Calcutta Linseed, three years 














old, kept throughout that period in 
an air-tight vessel, shielded against 


























light 


0-9324 


1-3 


192-5 


17403 


0-7 


0-70 


Finest St. Petersburg Linseed, three 














months old - - - - - 


0-9334 


1-3 


192-2 


177-25 


1-1 


0-88 


Finest St. Petersburg Linseed, seven 














months old 


0-9346 


1-3 


193-1 


176-23 


0-98 


0-66 


Baltic Linseed, commercial ; the seeds 














contained an admixture of ravison 
















0-9343 


1-3 


194-3 


170-06 


1-1 


0-73 


Finest and purest Baltic Linseed ; the 














sample was kept away from light 














for thirteen years - - - - 


0-9410 


7-2 


196-2 


176-84 


1-1 


1-95 



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120 MANUFACTUBE OF VABNISHES. 

IODINE AND SAPONIFICATION VALUE OF PRINCIPAL OILS. 



ou. 


Iodine Values. 


Saponiacati 


on Values. 


Min. 


Max. 


Average. 


Min. Max. 


Average. 


Candle-nut 


186-3 


163-7 


150 


184 ' 192-6 


188 


Beech-nut - - - 


102 


112 


108-109 


191 1 198 


195-5 


Cotton-seed 


102 


111-2 


106 


191 1 196-2 


193-5 


Butter - - 


26 


35 


33 


221 227 


224 


Cocoa-nut - 


3 


9-35 


8-5 


258 1 262 


257 


Cod-liver - 


123 


166 


144-148 


176 194 


182-187 


Earth-nut - 


87-3 


103 


94-96 


190 197 


194 


Hemp-seed 


140-5 


166 


160 


190 193 


191-5 


Hazel-nut - 


88-2 


86-9 


84-8 


191-4 197-1 


194 


Bone-fat - 


46 


55 


49 


, 


190-5 


Linseed ... 


170 


195 


178 


187-4 


195-2 


192 


Poppy-seed 


134 


143-3 


138 


192-8 


194-6 


193-7 


Walnut - 


143 


152 


150 


186 


197-3 


195 


Olive - 


79 


88 


82-83 


185 


196 


193 


Palm- 


51 


52-4 


51-5 


200 


202-5 


201-6 


Castor ... 


82 


85-9 


84-5 


176 


186 


180 


Beef-tallow 


35-6 


44 


39 


193 


206 


197 


Seal ... - 


96-5 


152-4 


128 


178 


196 


192 


Rape- 


98 


104 


100-101 


170 


179 


177 


Sesame ... 


103 


112 


108-109 


187 


192 


190 


Sunflower - - - 


122 


134 


128 


189 


194 


192 


Sperm - . . 


81-3 


84 


82-5 


117 


147 


135 


Grape-seed 


94 


99 


96 5 


178-4 


179 


178-7 


Whale - 


80-9 


130 


110 


188-5 


224-2 


192 


Japanese wood - 


149-7 


165-7 


160 


190-7 


196-1 


194 



Wijs* Modification of Determining Iodine Absorption of Oils, — 
Thirteen grammes of iodine are dissolved in 1 litre of glacial acetic 
acid on the water bath, and, after cooling, chlorine is passed through 
the solution until its titration strength is doubled, a rather sharp 
alteration in the colour indicating the point. The Wijs' solution may 
also be prepared with iodine bichloride, or with the monochloride, 
but, however made, it can be got ready in sufficient quantity to last 
for a long time without fear of its losing strength. In conducting 
the analysis from 10 to 20 drops of the oil are carefully weighed 
and put into a wide-mouthed stoppered bottle, pure chloroform or 
carbon tetrachloride is added, and 25 c.c. of the Wijs' solution contain- 
ing about 16*24 grammes ICl per litre are next put in. After standing 
for fifteen minutes potassium iodide solution is further added, and 
the volume made up to 150 c.c. with water. It is then titrated with 
thiosulphate in the usual manner. 

The Wijs' method agrees somewhat closely with the Hiibl, but 
the former gives rather higher results. Harvey found with rape oil 
(Hiibl's method) 101'6 and 104*9. Cod oil seems to give as much as 
7 or 8 per cent, higher by the Wijs* method than by Hiibrs. The 
advantages of the Wijs* process are rapidity (earth-nut absorbs 98*9 
per cent, of its full quantity in one minute), stability of solution, 
and quick and accurate results. 

The following table gives Wijs* results with raw linseed oils of dif- 
ferent origin : — jigitized by GoOglc 



THE DETECTION OP ADULTERATION. 



121 



its 



i I 1 1 1 1 i 1 1 1 1 1 1 1 1 I 1 1 i 1 1 1 1 1 1 1 1 1? I i 



00 



s Is i I I 



I I 



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a 
6 



II ill I lii I I li 

66 6 6 



n 



tH tH -^ O O <N »p O (N Oi p U3 <N « «0 -^Jt rH 0> 

a Oi Oi Oi 00 00 



2J ^25 Tjixo-* 000000 «o 

OOiOiOiOiOiCOOiC^Oi 



OTHr>eoo>iH«ot-ooo>coTH 



O 



•a 



• • > I I • I • I I I I I • • I II I 

• • ' • K0 I I « • I I I I I I I I I I I 









IE -& 



JSP 



S q3 00 P 






§ =-- = 






9^t 



fecS 



I I I I I I I I I 



icoS^g^ I iS^SS I I 18 

6666 6666 6 



iff 



I I I I I I I I 






5 



g-* 00 coco , , , <» I § I 
oocoeooo CO 00 

OiOiOiOiO ' ' ' Os'c3i' 



00000 



6 



6 



II <N iH I w>i 1— I 
coco coco 
' C3i OS • C3i Oi 



66 



0>Ci 

66 



I I Mil I I Mil 



66 



2^ 



op CO « «0 CO op "* >p »p p l><pp lr-0>qoc»<N b-O O 0<N »p(» l>>p« iH tH qp 

th do >b o o 6 b- « t-6»b >b>b ^ <»<N<N <N Oil 666 i) fc-6 -^ c»<Ndb 00 t- 

00^00)0^0)0)0) OOO0OOQOOOQ0OOOOQOQOQO000Ot«t«b-b*b«OOOOb*t>>b* 



s 
o 



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(4 

I- 

1 
s 



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122 MANUFACTURE OF VARNISHES. 

15. Mcllheny's Bromine Absorption Method, — About 0'2 gramme of 
the linseed oil to be tested is placed in a glass-stoppered bottle, 10 
c.c. of carbon tetrachloride added to dissolve the oil, and then 20 c.c. 
of third normal bromine in carbon tetrachloride run in from a pipette. 
Another pipetteful is run into another similar bottle. It is conveni- 
ent, but not absolutely necessary, that both bottles should now be 
cooled by immersing them in cracked ice. This causes the formation 
of a partial vacuum in the bottle. The bromine need not be allowed 
to react with the oil for more than a few minutes as the reaction 
between them is nearly instantaneous. Twenty-five c.c. of a neutral 
10 per cent, solution of potassium iodide is introduced into each bottle 
by slipping a piece of rubber tubing of suitable size over the lip of 
the bottle, pouring the iodine solution into the well thus formed, and 
shifting the stopper slightly so as to allow the solution to be sucked 
into the bottle, or, if the bottle has not been cooled, to cause the air 
as it escapes from the interior to be washed by bubbling through the 
potassium iodide solution. This prevents the loss of any bromine or 
hydrobromic acid. The iodide solution has been introduced, the 
bottle is shaken, and set in ice for a couple of minutes more, so that 
there may be no loss when the stopper is opened, caused by a slight 
pressure inside the bottle. The solution reaction causes some heat 
and consequent pressure. The free iodine is now titrated with neutral 
tenth-normal sodium thiosulphate, using as little starch as possible 
as indicator. At the end of this titration 5 c.c. of a neutral 2 per 
cent, solution of potassium iodate and a little more starch solution 
are added and the iodine liberated, on account of the hydrobromic 
acid produced in the original action of bromine on the oil, titrated 
with thiosulphate. From the figures so obtained, the total percentage 
of bromine which has disappeared is calculated, and the percentage 
of bromine found as hydrobromic acid, called the " bromine substi- 
tution figure,'* is also calculated, while from these two the *' bromine 
addition figure " is obtained by subtracting twice the bromine substi- 
tution figure from the total bromine absorption. If an oil contains 
rosin, rosin oil, or mineral oil, the fact will be brought out by this 
process, and an indication given by the figures so obtained as to 
which one is present. If the bromine substitution figure is normal 
the absence of more than a very small quantity of turpentine, 
benzine, rosin, or rosin oil is assured. The process can be carried 
out in the time necessary for weighing and titrations, as the standard 
solution, unlike the Hiibl solution, does not deteriorate on keeping 
if tightly closed, so that it is always ready for immediate use, and 
there is no waiting for some hours for the reagents to act upon the 
oil, as in the Hiibl process, for in this case the reaction takes place 
immediately. 

The bromine addition figure of linseed oil lies ordinarily between 
100 and 110. Age lowers the halogen figures of linseed oil. 

A low " addition figure " may also be caused by the presence of 
rosin, rosin oil, benzine or mineral oils, which have figures usually 



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THE DETECTION OF ADULTERATION. 123 

below 15 ; by the presence of some other seed oil. the commonest of 
this class being corn and cotton-seed oils, having figures in the neigh- 
bourhood of 73 and 63 respectively ; or (see p. 108) by the oil, in case 
it is a boiled oil, having been boiled in the old-fashioned way at a high 
temperature. If the ** addition figure " is very much higher than 
110, it will be found that the oil contains . turpentine, as all other 
foreign materials added have lower figures than Hnseed oil. 

The ** bromine substitution figure " of genuine linseed oil is 
commonly about 3. A much higher figure would point to turpentine, 
rosin, or rosin oil, which give figures from 20 to 90 ; to the presence 
of some petroleum product, as benzine, having a figure in the neigh- 
bourhood of 15, or a heavier petroleum oil, which may have as low a 
figure as Unseed, or may be much higher ; or to the presence of 
mineral acid in the oil, which may be allowed for by a separate 
determination of its amount, as described under the determination 
of the " acid figure ". 

It is a noteworthy fact that both the Hiibl and the " bromine 
addition figures " are practically the same for boiled oil as now made 
as for raw oil, whereas boiled oil made by the old process at a high 
temperature gave distinctly lower figures on account of the effects of 
the great heat upon the oil. 

The amount of bromine equivalent to the iodine absorbed as ex- 
pressed by the Hiibl figure has been calculated, and by dividing this 
result by the '* bromine addition figure," a figure was obtained for each 
oil which is intended to express, by the amount it exceeds 1,000, 
the amount of substitution of iodine which has gone on in the Hiibl 
iodine absorption. For example, if the figure obtained for an oil by 
the calculation described is found to be 1'075, it indicates that the 
Hiibl figure is in that case 7*5 per cent, higher than the true iodine 
figure, which should express the iodine absorption by addition. 

The ** bromine addition figure " is not sensibly affected by the 
length of time that the oil is allowed to remain in contact with bromine, 
but the ** bromine substitution figure " probably is. The difference 
between five minutes' and thirty minutes* contact does not appear, 
however, to be marked, unless the substitution figure is very high, 
as in the case of pure rosin or turpentine. 

In carrying out either the Hiibl or the bromine process upon oils 
it is necessary that an excess of iodine or bromine should be used 
amounting to as much as the oil absorbs. Many iodine figures on 
record are too low because this precaution was not attended to. 

It is beheved that more information is to be obtained as to the 
character of a sample of hnseed oil by determining the bromine figures 
than by any other single test. In the case of an oil of unknown 
character, it would in most cases be advisable to apply this test first 
to it (Mcllheny). 



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124 



MANUFACTUEE OF VABNISHES. 



16. The Percentage of Insoluble Bromine Derivatives. 

This determination is proposed by Hehner and Mitchell {Analyst^, 
Dec, 1898, vol. xxiii., p. 310). It depends upon the fact that linseed 
oil gives, when dissolved in ether and treated with bromine, com- 
pounds of glycerides and bromine which are insoluble in the ether^ 
while oil containing glycerides of oleic acid only, and even semi-drying 
oils like cotton-seed and com oils, give soluble compounds. Hehner 
and Mitchell obtain the following percentages of insoluble bromine 
compounds from different oils : — 

Per cent. 

Linseed oil 23-86 to 25-8 

Poppy oil 0*0 

Com oil 0-0 

Cotton-seed oil 0*0 

Olive oil 0-0 

Almond oil 0*0 

Bape-seed oil 0*0 

Whale oil 250 

Cod oil 34-5 

Cod-liver oil 42-9 

Shark oil 22-0 

The process, which seems to be a valuable one, detecting adul- 
terations of linseed oil with other seed oils, has been satisfactorily 
reported on by Mcllheny. Two samples of raw linseed, six samples 
of boiled linseed, two of com, and one of cotton-seed oil, tested by 
him, gave results agreeing substantially with those of Hehner and 
Mitchell. Two samples of mineral oil, one light and one heavy, one 
sample of rosin oil, and one sample of turpentine failed to give any 
precipitate of insoluble bromine derivatives. 




Fig. 29. — Apparatus capable of being Heated for Testing Drying, Viscosity,. 
Qumming, etc., of Oils, vdth graduated scale to left and thermometer to right. 

Kapidity of Drying and Weight of Oxygen Absorbed. 



17. Mulder pointed out the necessity of spreading the oils out 
thinly so that they did not dry on the surface and thus prevent the 
liquid underlayer from absorbing oxygen. He spread 3 grammes of 



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THE DETECTION OF ADULTERATION. 



125 



oil over 220 square centimetres so as to get about 0'016 gramme of oil 
per square centimetre. Under these conditions he noted the follow- 
ing increases : — 



Oil. 


Increase in 

Weight Per 

Cent. 


oa. 


Increase in 

Weight Per 

Cent. 


Poppy-seed - 

Walnut 

Linseed . - . 


12-2 

8-7 

11-9 


Linseed and Manganese 

Borate 
Linseed and Litharge - 
Linseed and Red Lead - 


12-4 
12-5 
18-2 



Casselman tried to lessen the time required by the oil to absorb 
its maximum of oxygen by heating 3 to 4 grammes of the oil for three 
hours daily up to 150° C. (302° F.), with the following results :— 



Oil. 


Behaviour after above Treatment. 


Linseed - - - 

Poppy-seed 

Hemp-seed 

Sunflower 


Dry after IJ to 2 days 
4 to 5 „ 
„ after a few days more 
Viscid and gelatinous after 3 months 



But this method is altogether too irregular for serious consideration. 
Kissling spread 10 grammes of several oils over 35 square centi- 
metres and exposed the same for ten days at the ordinary temperature, 
with the following results : — 



Oil. 



Olive 

Rape (crude) - 
Rape (refined) 
Neatsfoot (refined) 




^^6^ 



00 
005 
0000 
0065 



Oil. 



Cotton -seed - 
Raw Linseed - 
Boiled Linseed 
Triolein - 







0-545 
1-180 
3-400 
0-0 



Lwache*s Precipitated Lead Test, — The transformation of a drying 
oil into a solid elastic substance is due to an absorption of oxygen. 
Linseed oil absorbs 14 to 16 per cent, of its weight, and it is easy to 
directly measure the quantity absorbed, by imbibing in the oil a little 
spongy metallic lead well washed and dried in vacTW^ obtained by 



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126 



MANUFACTURE OF VARNISHES. 



precipitating a lead salt by a zinc plate ; the whole is exposed to air 
as long as the weight varies ; the increase in weight indicates the 
amount of oxygen absorbed. 

By this process, when conducted with the necessary precautions, 
the quantity of oxygen absorbed by any sample of linseed oil may be 
rapidly ascertained, and, whether a pure oil is being dealt with or an 
adulterated oil, or an oil already partially oxidised, in all cases it can 
readily be ascertained whether an oil corresponds with a given sample. 

This reaction ought to draw the attention of practical men, be- 
cause samples are often met with which, although equally genuine^ 
take longer time to dry. Now, the precipitated lead test indicates 
the difference in duration of the time taken by the oil for complete 
oxidation, and thus predicts beforehand the way in which any given 
oil will dry when applied to an appropriate surface on the large scale. 

Process, — ^t)ne gramme or thereabouts of the precipitated lead is 
weighed in a tared watch glass, then 0*5 gramme of oil is spotted 
upon it drop by drop, spacing out the drops in such a way that a 
little dry lead rests between each of them. At the end of two days 
the following results were noted in regard to oils in column I. The 
oils in column II. showed no results during the first two days. The 
figures in the column are the increase after a week. 



I. 

Oil. 


Increase Per 
Cent. 


II. 
Oil. 


Increase Per 

Cent. 


Linseed - - . 
Walnut - 

Poppy-seed - - - 
Cotton-seed - - - 
Beech-nut - - - 


143 
7-9 
6-8 
6-9 
4-3 


Colza - - - - 
Sesamum - - . 
Earth-nut - 
Rape - - - - 
Olive - - - - 


2-9 
2-4 
1-8 
2-9 
1-7 



Jean has tested Livache*s method with fish oils in dry air under 
a bell jar with H2SO4, with the following results : — 



Oil. 


Increase in 

Weight 

Per Cent. 


Oil. 


Increase in 
Weight 
Per Cent. 


Whale - 
Japanese Fish - 
Cod-liver - 


8-26 
8-19 
6-38 


Menhaden 

Sperm - - - 


5-45 
1-63 



Weger tested Livache's method against the same oil on a glass 
slab by itself, and also on a glass slab with both red lead and litharge 
as driers respectively. He found that the amount of lead in Livache's 
method must be increased in order to get a sharp maximum. 



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THE DETECTION OP ADXJLTEBATION. 



127 



Livacbe's Metbod. 
Increase in Weight. 


The same Oil 
spread on a 
Glass Slab. 


The same Oil with 6-6 

Grammes of Red Lead 

to 0*3188 Grammes 

of Linseed Oil. 


The same Oil with 10'4 

Grammes of litharge 

to 0-4910 Grammes 

of Linseed Oil. 


Days. 


Increase 
Per Cent. 


Days. 


Increase 
Per Cent. 


Days. 


Increase 
Per Cent. 


1 

2 

3 

4 

5 

6 

7 

8 

15 

42 

63 

85 


11-4 
12-2 
12-4 
12-6 

12-9 

13-5 
14-8 
17-2 
18-1 
20-4 


Gave a 

Maximum of 

17-1 

on a 

Glass Slab in 

5 to 6 Days. 


1 
2 
3 
4 
5 
7 


2-10 
11-30 
14-14 
14-65 
14-59 
14 06 


1 
2 
8 
4 
6 
7 


2-00 
11-30 
13-64 
14-32 
14-27 
14-21 



Weger found the following oxygen absorption addition figures : — 







Maximum 






Maximum 


ou. 


Days. 


Increase 
Per Cent. 


Oil. 


Days. 


Increase 
Per Cent. 


Bape-seed 


7 


7-61 


Electro Boiled 


lJ-2 


151-16-7 


Olive - 


20 


5-21 


Commercial Boiled 






Pine-seed 


29 


10-61 


(Hydrated Oxide 






Palm-kernel - 


13 


0-81 


of Manganese) - 
Commercial Boiled 


1-2 


14 7-14-8 


Air-blown Rape 


15 


7.71 






Hemp - - - 


4-4i 


13-4-13-6 


(Litharge) - 


16-24 


14-61-14-8 


Poppy-seed - 
Wood (Various) - 


a 


13-4 




hours 




13-4-16-9 


Boiled Linseed pre- 






Indian Linseed 


4J.6 


16-8-17-3 


pared with 3 per 






Commercial Lin- 






cent, of Bosinate 






seed - - - 


4i-8 


17-18-7 


of Manganese in 






English Linseed - 


8J 


19-7-19-9 


the cold 


24hrs. 


14-7-16 


Old Tanked Linseed 


3 


15-1-15-7 








Indian Linseed 






Boiled Linseed pre- 






(heated for a short 






pared with 3 






time at 160° 0.) - 


6 


17-0 


per cent, of Lead 
Manganese Bo- 






Indian Linseed 










Blown (oold) 


8 


16-7 


sinate in the cold 


— 


17-2 


Indian Linseed 






The same after 18 






Blown (hot) 


6J.6i 


8-2-9-3 


months' exposure 






Stand - 


18 


11-1 


to the air - 


— 


10-9 


Thickened - 


18 


10-7 


Boiled Rosin oil - 


7i 


23-3 

1 



Bishop's Silica and Bosinate of Manganese Test, — 1. Ten grammes 
of the oil are weighed in a capsule, and 2 grammes exactly of the 
rosinate of manganese added. The capsule is put into the water 



^ Oxygen absorption addition still proceeding. 



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128 



MANUFACTUEE OP VARNISHES. 



bath, stirring it from time to time until the complete solution of the 
rosinate, from five to ten minutes being sufficient for this. It is then 
cooled. 

2. One gramme of silica is weighed in a capsule with a flat bottom 
furnished with a little glass stirrer. With the aid of a dropping tube, 
a quantity of oil, as near as possible approaching 1*02 grammes (i,e,, 
1 gramme of oil plus 0'02 of rosinate), is allowed to fall drop by drop 
over the whole of the surface. Both the weight of the oil and the 
total weight are noted. By means of the stirrer the oil is mixed with 
the silica in such a way as to have a divided mass, perfectly homo- 
geneous, covering the whole of the bottom of the capsule. This is 
left at a temperature of from 17° to 25° C. in the case of drying oils, 
of 20° to 30° C. for the others, and weighed at the end of varying 
periods ; for instance, six hours, sixteen hours, twenty-two hours — 
that is to say, three times in the twenty-four hours. After each 
weighing the surface was renewed by agitation with the stirrer. The 
degree of oxidation is furnished by the maximum augmentation multi- 
plied by 100 when 1*02 grammes weighed exactly is operated on. 
Using pure linseed oil and the same oil with 2 and 4 per cent, of 
rosinate the following were the results. The linseed oil had a specific 
gravity of 0*9322 at 15° C, and through the experiments the tem- 
perature ranged from 20° to 25° C. : — 



Increase per cent 


No Drier 


2 per cent, of 


4 per cent, of 


at the end of 


added. 


Rosinate added. 


Rosinate added. 


6 hours 





12-35 


11-10 


22 „ 


0-60 


15-65 


15-50 


24 „ 


0-80 


15-85 


15-30 


30 „ 


2-50 


16-25 


15-30 


48 „ 


7-30 


15-65 


14-90 


72 „ 


15-00 


14-65 


14-10 


96 „ 


16-40 


15-15 


13-60 


120 „ 


15-30 


14-05 


13-20 


144 „ 


14-90 


13-75 


13-20 


168 „ 


14-30 


13-35 


13-20 


288 „ 


14-00 


13-25 


13-10 



These experiments showed in a decisive fashion the energetic 
action of rosinate of manganese as a drier, since this salt produced 
the total oxidation of the oil three or four times as quickly as in 
operating with simply divided oil. It also confirms the conclusions 
of the experiments of Cloez and those more recently made by Mulder, 
Bauer, Hazura and Livache on the formation not only of sohd pro- 
ducts but also of volatile products. If the oxidation is too strong, as 
in the case where 4 per cent, of rosinate was added, a final result is 
obtained very much more quickly and at the same time a feebler 
increase, this phenomenon being explained by reason of the formation 



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THE DETECTION OF ADULTERATION. 



129 



of a higher proportion of volatile products. In the experiments that 
follow, therefore, 2 per cent, of rosinate has been used : — 



Increase per cent, at 
the end of 


Pure Linseed Oil 

Sp, gr. 0-9322. 

Temperature 17° to 23° C. 


Linseed Oil containing 5 
per cent, of Rosin Oil 
and 5 per cent of 
Mineral Oil. 

Sp. gr. 0-9323. 

Temperature 17° to 23° C. 


6 hours 
22 „ 
24 „ 
30 „ 
48 „ 
120 „ 


13-50 
16-30 
16-40 
16-20 
15-90 
14-80 


1150 
14-80 
14-90 
14-80 
14-60 
13-80 



The influence of temperature is very great, and it would sedm 
useful in the case of linseed oils to operate at a temperature not 
exceeding 28° C, but above 17° C, in order to effect the oxidation 
in as short a time as possible. The experiments showed also the 
inferiority of exotic linseed oils of a low specific gravity, and also 
showed that it is possible to establish by a comparison the inferior 
quality arising from clever adulteration. 







Average degree 


Ratio 




Specific 


of maximum 


17-05 


Oils. 


Gravity. 


oxidation. 


X 


French Linseed - 


0-9827 


17-05 





Linseed from La Plata 


0-9304 


15-20 


1-12 


Hemp-seed - - - - 


0-9287 


14-40 


1-18 


French poppy-seed 


0924 


14-20 


1-20 


Commercial walnut 


0-924 


19-70 


1-28 


Demargarinated cotton-seed 


0-923 


8-45 


1-80 


Non-demargarinated cotton- 








seed - - - - 


0-924 


8-60 


1-98 


Senegal sesamum 


0-9215 


8-70 


1-96 


Indian sesamum - 


0-921 


7-40 


2-30 


African earth-nut 


0-916 


6-70 


2-54 


White earth-nut - 


0-916 


6-50 


2-62 


French colza - - - 


0-9142 


6-40 


2-66 


Indian colza ... 


0-9137 


5-85 


2-91 


Olive 


09155 


5-30 


3-21 



The degree of oxidation can therefore be advantageously used to 
control the iodine value, and in many circumstances it is even capable 
of replacing it with advantage. In fact, in addition to its great sim- 
plicity and the minimum cost of carrying it out, which makes it a 
very practical method for the industrial laboratory, this method fwr- 
nishes very often a more rational arid more complete indication than 
the Hubl number, as it permits many minor interesting details to be 
noticed. In consequence, this process will serve to fix the value and 
establish the nature of the identity of an oil, whether taken separately 
or compared with a type. Moreover, it may be applied in the case 

Digitized by VjOOQIC 



130 MANUFACTURE OF VARNISHES. 

of certain mixtures, not only of oils among themselves, but also of 
commercial products, such as lard and alimentary fats, which often 
contain very variable quantities of vegetable oils. In this last case, 
instead of oxidising directly either the melted and clarified fat or the 
fluid part extracted by pressure, the liquid fatty acids may be operated 
upon, separated from the solid acids by Halphen's process. The oil is 
saponified, the soap dissolved in water, and precipitated with acetate 
of lead. The lead soap is extracted with ether, and the ethereal 
solution of the lead salts of the non-saturated fatty acids is precipi- 
tated with weak sulphiuic acid. Indications still more interesting 
and more precise are obtained by taking the iodine value before and 
after oxidation. The determination of the degree of oxidation gives 
results in immediate connection with the value of the oils for certain 
of their industrial purposes, and, as has been shown, certain falsifica- 
tions can be detected by the process. Moreover, it will show whether 
recently crushed or old tanked oil is being dealt with. 

18. Maumen^s Test — 1. The sulphuric acid to be used in this ex- 
periment should be pure, of specific gravity 1*84:5, and should be kept 
in a well-stoppered and capped bottle. The stopper should not be 
left out a moment longer than that required to extract the necessary 
quantity. Have the acid in a bottle 6 inches high, with a thermo- 
meter inside. 

2. Counterbalance a glass tube, on foot, standing heat (about 
1^ inches in diameter and 7 ounces capacity), and weigh in accu- 
rately 50 grammes of the oil. 

3. Immerse both the sulphuric acid and the tube containing 
the oil in water contained in a tin vessel 5 inches deep, 2 quarts 
capacity, and apply heat. As soon as both the acid and the oil are 
at a temperature of 27° C, draw out 10 c.c. of the acid with a pipette 
and let it flow gradually at the rate of 1 c.c. every five seconds into 
the oil, without touching the sides, stirring very energetically all the 
time with the thermometer. After all the acid is in continue to stir 
exactly for half a minute, then move the thermometer more slowly, 
noting the exact degree at which it ceases to rise. 

k pure sample of oil should be tested in the same manner pre- 
cisely, immediately before the suspected article. No two persons, 
unless actually working side by side, will ever get absolutely identical 
figures, and rarely then. So delicate is the rise of temperature that 
the same operator must needs be careful to obtain constant figures on 
repeating the experiment on the same oil. 

In the case of linseed oil and fish oils the action is very energetic, 
abundant fumes being given off, whilst the mixture, assuming a gluey 
consistence, thorough mixing of the acid and oil is a matter of great 
difficulty. Moreover, it is not at all easy to obtain satisfactory read- 
ings of the thermometer, the more so as the latter has to be used to 
stir the oil. It is therefore advisable to mix linseed, etc., oils in 
known proportion with an oil on which sulphuric acid has no great 
action, such as petroleum lubricating oils. 



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THE DETECTION OF ADULTERATION. 



131 



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132 



MANUFACTUEB OF VARNISHES. 



Knowing the heat given out by mixing the mineral oil alone with 
sulphuric acid, it is easy to calculate how far its admixture with linseed 
oil has affected the latter. 

MAUMEN^'S TEST, RESULTS WITH TYPICAL OILS. 



Oil. 


Maumen^. 


Baynes. 


Archbutt. 


Allen. 


De Negri 
and Fabris. 


Linseed - - - - 


103 


104-124 




104-111 


122-126 


Hemp-seed - - - 


98 








— 


95-99 


Walnut - - - - 


101 











96 


Poppy-seed - 


74 


— 


86-88 


— 


87-88-5 


Niger-seed - - - 


— 


82 


— 


81 


— 


Sunflower 


— 








— 


72-75 


Soja-bean - - - 














117 


Cotton-seed (crude) 


— 


84 


70 


67-69 


— 


(refined) - 


— 


77 


75-76 


74-75 


— 


Olive - . - - 


42 


40 


41-45 


41-48 


32-37 


Dolphin - 


— 


— 


42 


41-47 


— 


Menhaden - - - 


— 


— 


128-128 


126 


— 


Cod-liver _ - - 


102-103 


116 





113 


— 


Whale (Arctic) 


— 


■ — 


— 


91 


— 


„ Antarctic - 


— 


— 


92 


— 


— 


Seal . - - . 


. — 


— 


— 


92 


— 



Specific Temperature Beaction (Thomson and Ballantyne). — The 
rise of temperature obtained by mixing 50 grammes of oil with 10 c.c. 
of sulphuric acid, divided by the rise of temperature produced by mix- 
ing 50 grammes of water with 10 c.c. of the same sulphuric acid, in 
the same vessel and under identical conditions, gives a quotient 
termed the specific temperature reaction. 



Origin of Oil. 


Authority 


Specific 
Tem- 
perature 
Reaction. 


Origin of Oil. 


Authority. 


Specific 
Tem- 
perature 
Keaction. 


Baltic - 
East Indian - 


Thomson and 
Ballantyne 


349 
320 


Biver Plate - 


Thomson and 
Ballantyne - 
Jenkins - 


320 
318 



19. Elaidin Test for Differentiating between Drying and Non-drying 
Oils, — This is a very simple test, requiring no costly apparatus, when 
applied according to Poutet's original instructions. The proper way 
to apply the test is as follows : — 

A. Apparatus required : — 

1. Supply of 2-ounce conical test glasses on feet. 

2. A swan-neck minim measure. 

3. Mercury \ lb. in narrow-mouthed stoppered bottle. 



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THE DETECTION OF ADULTEEATION. 133 

4. Glass rods rounded at one end and dubbed out at the 

other. 

5. Glass flask, 30 ounces. 

B. Preparation of the test solution : Weigh out in any suitable 
glass vessel, such as a small beaker, 60 grammes of metallic mercury, 
run it into the capacious flask ; place the latter in a vessel of water 
in a stink-closet, or in a good draught ; then add carefully and gradu- 
ally, a little at a time, 75 grammes of nitric acid, specific gravity 1*37 
(74° Twaddell). Keep the flask well immersed in the water to con- 
dense the fumes, which are partially retained by the solution and 
constitute its acting principle. Transfer to a well-stoppered bottle, 
and label it olive oil test with date, as it does not keep long. 

Process, — Pour into a 1-ounce conical test glass on foot 10 minims 
of the above solution. From a separate minim measure run in 100 
minims of oil on to the top of the mercury solution. Thoroughly 
incorporate the mercury solution and the oil by stirring continu- 
ously with a small glass rod, dubbed out at the end by having been 
heated till viscous in a bunsen or blowpipe flame, and then pressing 
it against a slab of slate, stone, etc. Eepeat the test on a known 
sample of pure olive oil, and with olive oil adulterated, respectively, 
with 5 per cent., 10 per cent., 15 per cent., 20 per cent., 25 per cent., 
and so on of any drying oil. The test is best performed at five o'clock 
at night, and the set of samples set aside until next morning at nine 
with their respective rods left in the glasses. 

Treated in this manner olive oil gives a canary-coloured hard 
mass which can be lifted completely out of the test glass by means 
of the glass rod, and while still adhering thereto if it be struck 
against the test glass it emits a metallic resonant sound or musical 
note. 

Most writers refer only to the time which the oils take to solidify 
under the action of this reagent. We prefer, as the result of pro- 
longed experience in the tesijing of olive oil, to take the ultimate 
hardness and colour after a reasonable time, say, 5 p.m. to 9 a.m., as 
the standard to go by, and our results have never been called in 
question. It would be well if innovating analysts would test the 
original process thoroughly before modifying it for the mere sake of 
the vainglory of adding one more useless modification to numerous 
others. 

Lallemantia Oil. 

French, Huile de Lallemantia ; German, Lallemantiaol, — Density 
at 20-21° C, 0-9336 ; solidifies at - 35° C. ; Hehner value, 933 ; Eeichert 
value, 1'55; saponification value, 185; iodine value, 162'1; melting-point 
of fatty acids, 22*2° C. ; solidification point of fatty acids, 11° C. ; iodine 
value of fatty acids, 166*7. This oil is extracted from the seeds of Lalte- 
mantia Iberica, Fisch et M.y& plant belonging to the Labiates, growing 
wild in the Caucasus, and cultivated as a farm crop in Eussia, near 
Kieff. Its iodine value is very high, thus ranking it amongst the first 



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134 MANUFACTUEE OF VAENISHES. 

members of the drying oils. Wood oil, however, surpasses it, although 
the drying properties of linseed oil would appear, according to Eichter, 
to be inferior to it. Eichter spread a little of the oil on a watch-glass, 
and after nine days' exposure it dried to a thick resinous coating. 
But the drying properties have possibly been overrated, and con- 
firmatory results are necessary. By heating the oil to 150° C. (302° 
F.) for three hours complete drying took place after twenty-four hours. 
The oxygen absorption by Livache's test was 15*8 per cent, after 
twenty-four hours, and for the mixed fatty acids 14 per cent, after 
eight days. 

Ten grammes of the oil at 18° C. treated with 2 grammes of con- 
centrated sulphuric acid gave an increase in temperature of 120° C. 
(248° R). 

Wood Oil.^ 

Wood oil, the best drying oil known, is produced by the oil tree 
of China and Cochin China, the ElcBococca vernicia (Tong Yeou) — a 
plant belonging to the Eurphorbiacea, or spurge worts, which flourishes 
on the banks of the Yanktse Eiver in China — the seeds of which con- 
tain 53 per cent, of oil, 80 per cent, of which is got by crushing. 
In China it is used to some extent as an illuminant, but its con- 
sumption is chiefly as a varnish for boats, houses and furniture. It 
is also largely used in the varnishing of the native umbrella, and in 
the manufacture of waterproof cloth, whilst it is practically a ne- 
cessity in the manufacture of the finest silks. Of late years it has 
even been used in the building of forts, forming with lime, sand and 
clay a material almost as tough as granite. In the western pro- 
vinces the oil is adulterated in order to lessen its cost and to bring it 
into consumption for " coarser '* purposes. Owing to the distance 
which the product has to be brought to export ship, the great cost 
of repacking (an absolute necessity) and freight, its lay-down price is 
heavy. 

Until lately the only literature on wood oil consisted of short 
papers by Davies and Cloez, but a large number of workers have re- 
cently busied themselves with this product, such as Holmes, De Negri 
and Sburlatti, Jenkins, Williams, Fraps, Jean, Kitt and Milliau. The 
crushing of wood-oil nuts has unfortunately not yet been done on a 
manufacturing scale in Europe, as there seems to be some doubt both 
of the regularity of the supply and of the value of the press-cake. 

There are no reliable stetistics of the Chinese wood-oil nut harvest. 
In 1899 Hankow and other Chinese ports exported about 30,000 tons 
of wood oil, and it is considered that China herself uses double that 
quantity. This would make the total output of oil about 90,000 tons, 
and of nuts about 160,000 tons. The nuts themselves are. not ex- 
ported. It seems fairly certain, however, that a real demand would 

^ Cloez published the results of a careful study of this oil in the Comptes 
Eendus de VAcad&mie de Science^ vols. Ixxxi., Ixxxii. and Ixxxiii. It must not be 
confounded with gurjun balsam, a hydrocarbide oil also put on the market as 
wood oil. 



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THE DETECTION OF ADULTEEATION. 135 

soon be followed by an increase in the cultivation of the nut. The 
well-known variabUity in the quality of wood oil is due on the one 
hand to its coming from different species of the tree {Aleurites cor- 
data), and which are as yet imperfectly known, and on the other 
hand to the very primitive manner in which the Chinese extract the 
oil. The exporters at Hankow recognise three sorts : pai-yu, hsin-yu 
and hung-yu, but do not themselves know whether the differences 
are due to different sources of origin or to one being a first, 
another a second pressing, or one being hot pressed, and another 
cold pressed, or other differences having existed in their treat- 
ment. The investigations, the results of which are given below, 
were carried out with a small quantity of nuts, of which the exact 
locality of origin is unknown, except that it is Chinese. A slightly 
modified form of arachis-sheller was found to extract the kernel 
perfectly, and the kernels were 52 per cent, of the weight of the 
whole nut. The shells are of no value, and this is a matter of 
great importance, for it is evident that freight would be saved if the 
nuts were shelled in China. It is true that the kernels are very prone 
to become rancid when deprived of the protection of their shell, but 
they would not suffer during the voyage if packed air-tight. The 
kernels gave 58*7 per cent, of oil by extraction with ether. A pres- 
sure of 350 atmospheres on the other hand, at 28° C, only gave 43*0 
per cent. The residue from this pressing, when hroken off and again 
subjected (between rollers) to a pressure of 350Titmospheres at 65° C, 
gave 10*7 per cent, of the 15*7 per cent, still remaining. Thus the 
total yield was 53*7 out of a possible 58*7 per cent. 

Hence the yield reckoned on the whole nut is 22*36 per cent, on 
the first pressing, and 5*56 per cent, on the second, with 24*08 per 
cent, of oil-cake. The oil from the first pressing was a pale yellow, 
and that of the second a pale orange, and more viscid than the first. 
The constants of both oils agreed substantially with those already 
obtained by other investigators. It was found, however, that by 
picking the nuts before pressing and rejecting any that showed any 
sign of rottenness, the acid number of the oil of the first pressing 
could be brought down to 0*9. The oil has also no longer the dis- 
agreeable characteristic wood oil odour, and can be kept for weeks in 
a well-stoppered bottle without developing it. If exposed to the 
air, however, it quickly acquires it. This seems to confirm Ulzer's 
opinion that the development of the smell is a result of oxidation. 
But possibly the oil could easily pass through a sea voyage, in well- 
tilled and closely stoppered vessels, without acquiring any of the dis- 
agreeable odour. The press-cakes are very poisonous, and contain 
53 per cent, of protein and 12*1 per cent, of fat. The Chinese use 
them for manure, and also burn them for the manufacture of lamp- 
black. If some means could be discovered of extracting their poisonous 
ingredients the high percentage of protein which they contain would 
make them an excellent fodder. 

Properties, — The oil, when of good quahty, is somewhat viscous, 



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136 MANUFACTUEE OF VAENISHES. 

pale amber in colour, rather dull, lacking that brightness which is 
seen in rape or cotton-seed oil. It has a peculiar and characteristic 
nutty odour and unpleasant taste. 

Solubility. — Chinese wood oil is soluble in ether, petroleum ether, 
chloroform, and also in amyl alcohol, but is insoluble in cold absolute 
alcohol. 

Drying Properties. — A coat of wood oil on a slab of glass dries 
completely in a few hours at the ordinary temperature. Light alone, 
without air, is said to cause it to dry. When heated to 200° C. it 
thickens ; at 260° to 280° C. the oil gelatinises, but the jelly does 
not stick to the fingers. It should therefore not be heated above 
180° C. UnHke other drying oils it does not dry from without in- 
wards, but the process goes on simultaneously through the thickness 
of the coat of oil. This oil is well adapted for mixing with linseed 
oil, the latter component giving elasticity and the former hardness and 
resistance, as well as an increase in drying properties. 

By reason of its great siccative power elsBococca oil can be suc- 
cessfully employed instead of linseed oil in making copal varnishes, 
and makes them very durable and elastic. It requires no boihng to 
make it drying, but when boiled with oxide of fead and dissolved in 
turps it makes a fine varnish for furniture without any resin. It can 
also be used for making paper and cardboard impermeable. Paper' 
prepared with it is transparent, and can be written on with ordinary 
ink. Another use of elseococca oil is to replace linseed oil in the 
manufacture of oil colours, thereby escaping the darkening effect of 
the latter oil. 

The attention of varnish manufacturers is directed to this oil. It 
is a known fact (says Livache) that large quantities are yearly im- 
ported into England, but for what purpose is unknown. Now its 
remarkable drying capabilities in the cold, and without previous heat- 
ing, suggest to him its direct use in England in the manufacture of 
high-class varnishes. This assertion has recently been reiterated by 
Ferdinand Jean. 

But against its having been used to any extent in England, at 
least until recently, is the fact that the British oil merchants, on the 
other hand, advertised it as being extensively used on the continent. 

The results of experiments with this oil are very conflicting ; none 
of them, moreover, seems to have been undertaken in a truly scien- 
tific spirit. Instead of trying to find out the cause of the gelatinisa- 
tion of the oil on heating, unscientific attempts on rule-of-thumb 
principles have been made to make concoctions from it somehow or 
other, so that it may dry after the manner of linseed oil. The ex- 
amination of this oil will well repay thorough investigation, and 
possibly it may be found to contain a principle analogous to bird-Ume 
or the serum of india-rubber. In any case, all efforts should be con- 
centrated, in the first instance, to the isolation of the gelatinous 
principle and the examination of its properties. 

In heating wood oil for the purpose of making varnish it must 



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THE DETECTION OF ADULTERATION. 137 

always be borne in mind that the temperature must never exceed 
180° C, as the oil then gelatinises and will not mix with the other 
ingredients of the varnish. But with care the result is invariably 
extremely good. If the oil be heated with a drier and then thinned 
with French oil of turpentine the result is always good, although pro- 
longed stirring is necessary. Experiments have shown that borate of 
manganese is not a suitable drier for wood oil, but borax answered 
extremely well. Mixtures of wood oil and linseed oil were also tried ; 
the varnish dried in twenty-four hours on glass, and after a Httle 
became perfectly hard and transparent. But when the dried varnish 
was exposed to the weather, damp, dew and rain loosened its adhesion 
— which was, however, fully restored by exposure to dry air or sun- 
light. On wood the varnish resisted very much better, especially 
when mixed with zinc white. 

The following are typical experiments made on wood oil : — 

(a) Fifteen pounds of wood oil having been warmed up, 5 lb. of 
acetate of lead were added to it, a little at a time, the heat being kept 
up until solution was complete. Ten pounds of gum resin were then 
added, and when this was melted the varnish was thinned with 10 
lb. of French turpentine oil. The varnish so prepared dries in ten 
hours. A coating of it on tinplate, which was then steeped in a solu- 
tion of sodium carbonate for twenty-four hours, was not affected 
except as regards its colour. The latter was made somewhat paler, 
but the adhesiveness of the varnish was not diminished. Varnishes 
made with Unseed oil and subjected to the same treatment were 
practically destroyed by the alkaline solution, and could be afterwards 
removed without difficulty. 

(b) Ten pounds of rosin were melted up with 5 lb. of borax. On 
to this mixture 15 lb. of wood oil were poured. The whole was then 
heated up and mixed with 20 lb. of French turpentine oil. The 
varnish thus obtained dried rapidly for an hour, but as soon as the 
turpentine had all disappeared the rate of drying became very much 
slower, and after fifteen hours the varnish was still sticky. This 
seems to indicate a good varnish for gilding. The varnish was 
completely dry in forty-eight hours. 

(c) This experiment resulted in a very good varnish, which, how- 
ever, requires very great care in its preparation. Fifteen pounds of 
wood oil were mixed with 2 lb. of gum resin and driers, and the 
mixture was heated to frothing. Then 10 lb. of rosin were added, 
and when the latter was melted the heating was continued to as high 
a temperature as possible without gelatinising the wood oil, careful 
stirring being kept up until the liquid began to seem stiff. The 
vessel was then removed from the fire, and 40 lb. of French turpen- 
tine oil were carefully and thoroughly stirred into its contents. The 
varnish so prepared looks a bit turbid at first, but becomes quite 
clear within fourteen days. Spread on glass it dries to a hard and 
elastic coat in eight hours, or ten at the most, and on wood it dried 
in five hours. When applied to glass it had a fine lustre, and was 



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138 MANUFACTURE OF VARNISHES. 

entirely transparent. Any resin can be used for this varnish pro- 
vided its melting-point is below 180°, as is, for example, the case wi^th 
soft manilla copal. 

(d) The varnish made by this process would suit admirably as a 
thinning medium for oil colours. The ingredients were 15 lb. of wood 
oil, 15 lb. of Unseed oil, and 4 lb. of rosin. After the usual heating 
the varnish is thinned with 20 lb. of French turpentine oil. The 
varnish so prepared dries within twenty-four hours. As above men- 
tioned, its adhesion is destroyed by damp. In spite of containing 
linseed oil it always retains a whitish tinge. 

The odour of the Chinese wood oil is a very peculiar one and 
adheres to the dry coating made with it ; it adheres so strongly that 
it is plainly noticeable even after oilcloth-like goods dried in hot air 
have been lying for months, the same as oilcloth will always, even 
after years, smell of linseed oil. Naturally, this pecuhar lard-like 
odour also shows itself with the varnishes produced from the oil, and 
it therefore becomes necessary to remove it by some process. 

In the manufacture of leather and waxcloth an odourless and 
cheap varnish, which will dry very quickly, is a prime desideratum. 
Until lately dry Unseed oil was the favourite substance used. Of 
late, however, wood oil has been tried, and gave highly satisfactory 
results in respect of drying quaUties, but had the great drawback of 
possessing a very disagreeable smelL The foUowing four methods 
have been tried with a view of removing this only obstacle to its re- 
placement of drying oil which is considerably dearer : — 

1. Extraction of the odorous bodies by solvents. # 

2. Extraction of the odorous bodies (which are possibly aldehydes 
and ketones) by sodium bisulphite. 

3. Treatment with substances at the same time bleaching and 
deodorising. 

4. Treatment with superheated steam. 

We proceed to treat of these four methods seriatim, 

1. The solvent principaUy tried was alcohol, in strengths of 20 
and 40 per cent. When the oil had separated out after having been 
shaken up with the spirit, it was dried in a stream of warm carbonic 
acid. It is true that the disagreeable smeU was diminished, but the 
results were unsatisfactory, even without regard to the cost of the 
method. 

2. This method was tried by boiling the oil for six hours with 
twice its volume of a 10° B. solution of sodium bisulphite with a re- 
flux condenser. The oil was then washed with water from the excess 
of bisulphite. Its evil odour was not then appreciably less. This 
shows clearly that the malodorous substances present are neither 
ketones nor aldehydes. 

3. Animal charcoal, silicate of magnesium and the residues of the 
manufacture of potassium ferrocyanide were tried, without success. 

4. By this method very interesting results were got. The first 
trial consisted in blowing steam at 130° C. through the wood oil for 



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THE DETECTION OF ADULTERATION. 



139 



eight hours. The nasty smell was perceptibly lessened, but the oil 
partly solidified on cooling. When the steam was used at 165° C. a 
marked diminution of the bad odour took place, even in two hours, 
and in five there was very little smell of any kind, what there was 
being much hke that of linseed oil. In twelve hours the oil had 
begun to deposit and had regained some of the disagreeable odour. 
This recrudescence of the smell was, however, only slight when the 
oil was cooled without contact with air, showing that the action of 
atmospheric oxygen has probably something to do with the formation 
of the evil-smelling substances. 

Attempts to conceal the bad odour were made, especially with 
birch-tar oil, but were quite unsuccessful. 

CHEMICAL AND PHYSICAL PROPERTIES OF WOOD OIL. 
(Refractive Index, 1-603.) 



Observer. 


Density 
atl5°C. 


SoUdification 
Point. 


Hehner's 
Value. 


Saponifi- 
cation 
Value. 


Iodine. 


Davies and Holmes 

De Negri and Shurlate - 

Jenkins - - - j 

Ulzer - - - - 

Willia-ms - - | 


0-940 
0-936 
0-9343: 
0-9385 

0-9415- 
0-9432 


lbelow-17°C. 
\ 

i 


96-96-4 
96-3-96-6 


211 
166-172 

194 1 

194 
/ 190-7- 
U96-1 


169-161 
149-7- 
166-7 
162 
166-4- 
165-6 





FATTY ACIDS. 






Observer. 


Melting-Point 
Degrees C. 


Solidification 

Point 

Degrees C. 


Iodine 
Value. 


Heat of 
Bromination. 


De Negri and Shurlate - 
Jenkins - . - - 
Williams 


43-8 

30-37 

40-49-4 


31-2 
34-0 
37-1 


169-4 
144-1-160-1 


21-22-1 



Hemp-seed Oil. 

Hemp-seed oil is expressed from the seed of the hemp plant 
{Cannabis sativa), a plant belonging to the family of UrticacecB, and 
from the fibres of which cordage, ropes, etc., are spun. Hemp is 
extensively cultivated in France, Kussia, India, etc. Freshly ex- 
pressed oil is greenish yellow ; however, after a time the green tint 
disappears, the oil assuming a brownish-yellow colour. It has a 
powerful disagreeable odour of hemp and a bitter taste. The oil does 
not dry so well as linseed oil, which it is used to adulterate. It finds 
a legitimate use in the manufacture of soft soap. 



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140 MANUFACTUEE OF VARNISHES. 

CHEMICAL AND PHYSICAL PROPERTIES OF HEMP-SEED OIL. 





Density at 
15° C. 


Solidifi- 
cation 
Point. 


Sapon fi- 
cation 
Value. 


Iodine 
Value. 


Man- 
menu's 
Test 


Oleore- 
fractO- 
meter. 


Allen 


0-926-0-931) 


Thick 










Benedikt - - - 


- \ 


at 





167-6 





— 


Ch&teau - 


0-9270 J 


-16°C. 


— 


— 


— 


— 


De Negri and Fabris 


0-9280 ) 
0-9276 [ 


solidifies 


192-8 


140-6 


96-99 


— 


Fontenelle 


at-27°C. 











— 


Hiibl - - 


— 


— 


— 


143 


— 


— 


Jean - - - 


— 


— 


— 


— 


— 


+ 30 


Massie ... 


0-9266 


— 


— 


— 


— 


— 


Maumen^ 





— 








98 


— 


Shukoff - 


, 





192-194-9 


167-166 








Souchere ... 


0-9266 


— 


— 


— 





— 


Valenta - 


— 


— 


193-1 


— 


— 


— 



FATTY ACIDS. 





Melting- 

Point 
Degrees C. 


Solidifica- 
tion Point 
Degrees C. 


Mean 

Molecular 

Weight. 


Iodine Value. 


Acetyl 
Value. 


Benedikt and Ulzer- 
De Negri and Fabris 
Morawski & Demaki 
Htibl 


17-19 
19 


14-16 
16 


* 280-6 


141 
122-126-2 


7-5 



PoppY-SEED Oil. 

Poppy-seed oil, so highly esteemed by artists, is obtained by 
pressing the seeds of the poppy {Papaver somniferum) , indigenous to 
the Eastern Mediterranean countries, but cultivated generally all over 
the world, partly for opium, partly for the oil in the seeds. There 
are two varieties of the poppy : Papaver albtim, D.C., with white 
seeds, and Papaver nigrum j D,C.y with black seeds. The white poppy 
yields the best oil, and is the seed used for medicinal purposes. The 
black poppy is the variety most extensively cultivated, as an oil 
producer being the most profitable. The yield of fatty oil is about 
the same in both varieties, viz,, about 60 per cent. 
According to Sacc the poppy seed contains : — 

Oil 54*61 per cent. 

Protein 23*26 

Albuminoids 12 ,, 



Cellulose 
Ash 



6 
2 to 3 



Poppy seed does not contain morphine as alleged. 



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THE DETECTION OF ADULTEEATION. 



141 



Extraction. — The poppy heads are opened after being partially 
dried, and their contents discharged on to an iron plate ; they are 
then winnowed to remove fragments of the capsule, and afterwards 
ground to meal, which is packed in bags made of canvas and pressed, 
the oil being caught in tubs, where it is left to settle and thoroughly 
clarify. Two kinds of oil are on the French market. The white salad 
oil, the oil from the first pressing of the best quality seeds. This oil 
is almost colourless, or of a very pale golden yellow. The second 
quahty, used for technical purposes, is the result of the second press- 
ing at a higher temperature and is much inferior. Sometimes it is 
"the result of pressing inferior seed. The white, freshly extracted oil 
is inodorous with a bland flavour ; it is thus largely used as salad oil. 
Unsoimd oil is acrid. 

Destructive Distillation Products, — When subjected to dry distilla- 
tion by heating over a gas flame *' without boiling," poppy oil yields 
a consistent oleaginous substance which partly solidifies on cooHng, 
and has a faintly acid reaction, but does not cede to water any trace 
of sebacic acid. If, when distillation ceases, a fresh receiver be 
provided, and the heat increased, the oil begins to " boil," gives ofiF 
acrolein, and an oily distillate comes over which gives up to water 
an acid liquid containing sebacic and acetic acids. By stopping the 
distillation when half the oil has passed over the residue left in the 
retort forms, when cold, a thick, viscid mass, slightly coloured, and 
possessing many of the properties of the anhydride of hnoleic acid, 
which easily melts when warmed. 

Besides the solid glycerides of stearic and palmitic acid, poppy-seed 
oil contains oleic, linoleic (in large quantity) and linolenic acids. 

Percentage of Free Fatty Acids, — The oil contains varying amounts 
of free fatty acids. The following percentages were found by various 
observers : Eechenberg, 2*09 ; Salkowski, 2 '29. Nordlinger found 
{a) in 26 samples of expressed salad oil 0*70 to 2*86, average 1*92 
{h) in 5 expressed commercial samples 12*87 to 17*73, average 15*37 
(c) in 5 extracted samples 2'15 to 9*43, average 4*72. 

Poppy-seed oil is not often adulterated, but when sophisticated it 
is generally with sesame, which can be detected by the lower iodine 
value and the Badouin reaction. 



FATTY ACIDS. 





Benedikt and 
Ulzer. 


De Negri 
and Fabris. 


Hubl. 


Thomer. 


Melting-point Degrees C. - 
Solidification Point 
Saponification Value - 
Mean Molecular Weight 
Iodine Value - - - 
Acetyl Value 


279-1 
13-1 


20-21 
139 


20-6 
16-6 


20-6 
16-5 
199 

116-3 



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142 



MANUFACTURE OF VARNISHES. 



O 
Q 

o 



M "S 

^1 




+ 23-86 
74-6 at 26° 
G. (Zeiss's 

Inst.) 


Haumeni's 

Test. 
Degrees C. 


86-88 
87-88-6 


1 1 ? 1 1 1 1 1 1 1 


Is 

11 


133-7-137-1 

186-8-137-6 
137-6-143 

186 


184 

134-186 

134-185 
138-6 


8| 
ll 


189-1968 

198-6 
197-7 


192-8 

193-194 
194-6 


1^ 


1 1 1 l|| 1 1 1 1 1 1 1 1 1 1 1 1 1 1 


Solidifi- 
cation Point 
Degrees C. 


-18 


2 
1 1 1 1 1^1 1 1 1 

1 


1 




0-924-0-937 
0-8788 

0-9262 
0-9256-0-9268 

0-927 


0-9246 
0-9246 


d 


s| IS| IS 1 1 1 


1 1 1 1 ISS 1 1 1 


O 


Allen .... 
Archbutt ... 
Beckurts and Seiler 
Clarke .... 
Grossley and Le Sueur - 
Dietzel and Kreszner - 
De Negri and Fabris - 
Dieterich - - - 
Gerard - . - . 
Hiibl ... - 


Jean . . - - 

Mansfeld ... 

Maumen^ ... 

Moore ... - 

Shukoff- 

Souchere - . - 

StillweU 

Thomer 

Ulzer - - - . 

Valenta 



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THE DETECTION OF ADULTERATION. 143 

Walnut Oil. 

This oil, known as nut oil, is a drying oil, and must not be 
confounded with other non-drying nut oils. It is obtained from the 
kernel of the common walnut, Juglans regia, (Juglans = Jovis glans 
or Jove's acorn,) 

Artists' Oil, — ^The kernels are peeled and pressed in the cold, when 
they yield a rather cloudy oil diflScult to clarify, of a pale yellowish 
green tint, equal to, if not superior, in drying propensities to linseed 
oil, with an agreeable smell and nutty flavour. 

Virgin OU, — The walnut kernels are not peeled, but the fully 
matured nuts are stored for two or three months until decomposition 
sets in, when the kernels are pressed, yielding in the cold 25 per 
cent, of their weight of virgin oil. The oil expressed in this manner 
is used as an edible oil, and as a substitute for linseed oil. 

Second Quality Oil, — The marc from the first pressing is ground 
with hot water and again pressed, and the dark inferior oil, with an 
acrid taste and smell, thus obtained is used as a paint oil. 

Walnut oil dries to a more elastic film or coat, with less tendency 
to crack than linseed oil. For fine, delicate and white colours the 
better qualities of walnut oil are highly prized by artists on account 
of their being almost colourless, but their cost is too great for general 
use. 

Genuine walnut oil is difficult to procure. To make sure of its 
purity it must be extracted from the nuts by those who want to use 
it. The Smithsonian Institute, Washington, purchased the following 
samples as genuine walnut oil : — 

No. 1. Walnut Oil, White. — This article was colourless, of 
sweetish taste, with a peppermint-like flavour, and soluble in water 
and 92 per cent, and 50 per cent, alcohol. Further investigation 
showed it to be diluted glycerine, flavoured with a menthol-like body. 

No. 2. Walnut Oil, Cone, — The word concentrated immediately 
cast a halo of suspicion about this oil, and, on submitting it to a 
fractional distillation, about 80 per cent, came over between 78° and 
85° C, which was chiefly ethyl alcohol. Then the thermometer rose 
rapidly to 205° C, which is the boiling-point of nitrobenzine (oil of 
mirbane), and the odour confirmed the boiling-point. A small amount 
of non-volatile matter was left. 

When it is remembered that oil of walnuts is chiefly used by 
artists for paints, because it dries into a varnish which is less liable 
to crack than linseed oil varnish, the enormity of such adulterations 
becomes self-evident. 

Having been unable to secure an oil of good quaUty, walnut 
kernels were secured, ground, and the oil expressed by means of a 
hydraulic press. In this way 25 per cent, of oil was obtained, while 
the kernels actually contained 66 per cent, of oil. It was thus deemed 
of interest to investigate the oil, inasmuch as no such examination 
seems to have been made. 



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144 



MANUFACTUEE OF VAENISHES. 



The oil generally used is that obtained from Juglans regia, L,, a 
tree indigenous to Persia, and cultivated in Europe and America. 
The kernels of this nut contain from 30 per cent, to 40 per cent, of 
"virgin" oil. The fresh cold drawn oil is limpid, nearly colourless 
or pale greenish yellow, and of agreeable taste and odour, has a 
specific gravity of 0*925 to 0*9265 at 15° C, saponification number 
186-197, iodine value 142 to 151*7, fusing-point of fatty acids 16° to 
20° C, dries well, and is said to be brought into U.S.A. from France 
and Switzerland in 110-gallon tuns. 

Hickory-nut oil resembles the above walnut oil very much, and 
is known as ** American nut oil ". 

Wm. T. Brant says ** oil of black walnuts is sometimes expressed, 
but is of little value '*. On examining the cold pressed black walnut 
oil, the following physical and chemical constants were obtained. It 
is limpid, of a straw-yellow colour, possesses a pleasant, agreeable, 
walnut-like odour and taste, becomes turbid at 12° C, has a specific 
gravity of 0*9215 at 15° C, saponification number 190*1-191*5, acid 
number 8*6-9, ether number 181'5-182*5, Hehner's number 92*77, 
Eeichart-Missel value 15 c.c, iodine value 141*4-142*7, melting-point 
of fatty acids 0° C. 

The drying quahties are excellent, equal, if not superior in this 
respect, to linseed oil, leaving a tenacious, flexible, transparent film. 
An artist, on using it, pronounced it a very satisfactory article for 
fine painting. 

By a German process patented by Th. C. Graham, I. H. Kellog 
and W. K. Kellog, D.E.P. 109,237, the oil is extracted from the nuts 
by roasting them between 150° and 180° C, 302° and 356° P., and 
the shelled kernel made into a paste and mixed with water at 55° C. 
(32 litres of water to 100 kilogrammes of nuts when the oil floats 
to the surface). 

FATTY ACIDS. 



Observer. 


Melting- 

Point 

Degrees C. 


Solidifi- 
cation 
Point. 


Mean 

Molecular 

Weight. 


Iodine 
Value. 


Acetyl 
Value. 


Benedikt and Ulzer - 
De Negri and Fabris - 

Hiibl 

Kebler .... 


16-18 

20 
16-20 


16 


273-5 


16005 


7-6 



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THE DETECTION OF ADULTERATION. 



145 



H 
"A 
< 



II 


' ill" '^il "III"' 

^^ + CO 


Maumen6 

Test 
Degrees C 


1 S ^ 1 M 1 l.jo II 1 1 II 1 




143-1 

144-6-146-1 

147-9-151-7 

145-7 

143 

142-151-7 

143-3 
147-9-148-4 


d 
o 

F 


192-5 

193-81-197-32 
188-7 

186-197 
194-4 

196 


Solidifi. 
cation 
Point. 


1 


at-16°0. 

Solidifies 
at- 27-5° 0. 


1 




6 


0-9269 
0-9265 

0-926-0-9265 

0-9255-0-9260 
0-928 
0-919 
0-871 
0-926 


o 


s 


s s 1 II IS II laasss i 


O 


1 

< 


Crossley and Le Sueur 

De Negri and Fabris - 

Dieterich - 

Hazura - _ - 

Hiibl - - - - 

Jean - - - - 

Kebler - - - 

Maben - - - 

Maumene - - - 

Peters 

Petkow - -, - 

Saussure - - \ 

Souchere - - - 
Valenta 



10 



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INDEX. 



Absorption by linseed oil of bromine, 
122, 123 ; of chlorine, 74 et seq, ; of 
iodine, 79, 80, 117-21 ; of oxygen, 
1, 26, 27, 84, 72-74, 124-80. 
Acetate, calcium, 89. 
Acetates of lead, normal and basic. See 
under driers. 

manganese, 37, 89. 

Acetic anhydride, etc., test for rosin oil, 

103, 104. 
Acid, acetic, glacial solubility of rosin 
oil in, 112 ; insolubility of 
mineral oil in, 112. 
in Wijs' iodine method, 120. 

— hydrochloric, in oil refining, 20; 

linoleic, linolenic and linozio, 22 
et seq. ; nitrous, 21 ; nitric, 19, 62, 
64, 68 ; stearic in printing ink, 70. 

— sulphuric, in oil refining, 19 ; value 

of linseed oil, 112, 118 ; of rosin, 
113. 
Acids, fatty, iodine value of, 79 ; melting 
point of, 101. 

— refining oils by, 19. 
Acrolein, 53. 

Adulteration of linseed and other oils, 

94-146. 
African earth-nut oil, 129. 
Ageing of oil, 126 et seq. 
Agitators, mechanical, in oil boiling, etc., 

48-61. 
Agricultural societies and linseed oil, 

18, 14. 
Aignan polarimetric tests for rosin oil 

in linseed oil, 109, 110; in paint, 

110. 
Air, oxygen absorbed from, by linseed oil 
in drying, 1 et seq, 

— blowing of linseed oil, 60, 68, 69, 79. 

— boiling oil by, superheated, 62-54. 
Alcoholic potash, 112, 114. 
Aleurites trUoha^ 4. 

Alkaline linoleates, 87, 90, 91 ; rosinates, 
87, 91. 

— solutions, linseed oil substitutes at- 

tacked by, 2 ; use of, to clean o£E ink 

from type, 64. 
Almond oil, 100, 106, 124. 
Alum, a useless drier, 80. 



Alumina in linoleum, 61. 

— salts in oil refining, 16. 
American linseed, 6; petroleum oils, 

117. 
Analysis of linseed, 6, 7 ; cake, 7, 8 ; oil, 
96-133 ; poppy-seed, 140. 

— manganese borate, 9 ; rubber substi- 

tutes, 77-88. 

Aneroid thermometer, for use in oil boil- 
ing, 41. 

Anglo-American oil, mill mleushinery, 8- 
16. 

Aniline lakes in printing ink, 66 ; violet 
in printing ink, 68. 

Animal charcoal in oil refining and 
bleaching, 16, 17. 

Antarctic whale oil, 182. 

Apricot oil, 100. 

Arachis oil. See earth-nut oil. 

Archangel linseed oil, 121. 

Arctic whale oil, 182. 

Argentine linseed, 6. 

Artists' oil, 20, 143. 

Asphaltum in printing ink, 70. 



B. 

Baltic linseed oil, 5, 119, 121, 132. 
Bankoul (candle-nut) oil, 4, 120. 
Barium plumbate as a drier, 31. 
Basic acetate of lead, 20, 86. 
Beech-nut oil, 100, 109, 120, 126. 
Benzene in rubber substitute making, 

76 ; in linseed oil, 110. 
Binding agents for pigments, drying oils 
as, 2, 3. 

resins in varnishes, drying oils 

as, 8, 4. 
Bink's oil-boiling process, 82. 
Bishop's polarimetric test, 103 ; drying 

oil test, 127-130. 
Black, blood, 66 ; blue, printing ink, 66 ; 
carbon gas, 66 ; cork, 66 ; ivory, 66 ; 
lamp, 66 ; wine lees, 66. 

— mustard oil, 100, 108. 

— oxide of manganese, 88. 

— walnuts, oil of, 144. 
Bleaching of linseed oil, 15 et seq. 
Blowing air, hot and cold, through lin- 
seed oil, 46, 50, 68, 59, 79. 



(147) 



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148 



INDEX. 



Blue-black printing ink, 66. 

Blues, for printing ink, 70. 

Boiled linseed oil, 34, 35, 54, 56. See lin- 
seed oil boiling. 

for printing ink, 61, 71. 

— rosin oil, 127. 

Boiling linseed oil processes. See linseed 
oil boiling. 

*• through bunghole," 34, 92. 

Boric acid, 30. 

Bonis' oil- boiling process, 32. 

Britain, Great, flax cultivation in, 5. 

Bromine, addition and substitution 
compounds of linseed oil, 121-23 ; 
of rosin, 97. 
— derivatives, 124. 



Gake-paring machine, 11, 12. 
Calcined magnesia, 16, 64. 
Calcium acetate, 20. 

— plumbate as a drier, 31. 

— sulphate, 89. 
Canada balsam, 65, 70. 
Candle-nut oil, 4, 120. 
Cannabis saliva^ 4, 189. 
Canvas waterproof, 73, 77. 
Carbohydrates, in linseed, 6 ; in cake, 7. 
Carbonic acid evolved on drying, 24. 
Camauba wax, 70. 

Castor oil, 23, 81, 98, 100, 104, 106, 120, 
Catalytic action of driers, 29, 31. 
Caustic alkali, 16, 19, 20, 21, 87, 90, 115. 
Chalk in patent driers, 93. 
Charcoal, animal, 16, 17, 30; wood as 

fuel in oil boiling, 41. 
Chemical composition of linseed, 6. 

— constitution of linseed oil, 22 et 

seq, 
rubber substitutes, 77-83. 

— and physical constants of drying oils, 

hemp seed, 140 ; linseed, 96-133 ; 
lallemantia, 133 ; poppy-seed, 141, 
142 ; walnut, 144, 145 ; wood, 134- 
39. 
Chinese blue, 68. See Prussian blue. 

— wood oil, 4, 134. 
Chinoline lakes, 66. 

Chlorine, bleaching oils by, 17-20. 

— on rubber substitutes, 29. 
Chloroform in iodine value reagents, 118. 
Chlorophyll, 16, 17. 

Chrome yellow, 66. 
Chromic acid, 37. 
Citrates of manganese, 37. 
Cloez, influence of coloured light on 
drying, 24. 

— on wood oil, 128. 

Closed flash point apparatus, Gray's, 

104, 106. 
Coal-tar naphtha, 110. 
Cochineal lakes, 66. 



Cocoanut oil, 104, 120. 

Cod oil, 100, 106, 120, 124, 126, 131, 

132. 
Coil, steam, oil boiling by, 46. 
Coke as fuel in oil boiling, 41. 
Cold, crushing of linseed in, 7. 
Colour of raw linseed oil, 95 ; of boiled 

oil, 55, 85, 95. 
— tests for oils, 95, 101, 104. 
Colours for printing ink, 66, 68-70. 
Coloured light, influence on drying, 

24. 
Colza oil, 2, 3, 93, 100, 107, 109, 120. 
Concentrated driers, 91, 92. 
Condenser for oil boiling fumes, 43, 44. 
Copaiba balsam, 65. 
Copper chloride, 68. 
Cork black, 70. 
Com oil, 107, 124. 

Cotton-seed oil, 16, 81, 98, 100, 104, 106, 
107, 109, 120, 124, 126, 129, 131, 132. 
Crushing of linseed. See linseed, crush- 
ing of. 
Cucumber oil, 4. 
Cucumus sativiis, 4. 
Curd soap, 65. 



D. 

Darkness retards drying, 24. 

Debloomiug rosin oil, 95. 

Definition of drying oils, 1 et seq, 

Demargarinated cotton-seed oil, 129. 

Density of linseed, etc., oils, 96, 98, 119, 
129, 133, 139, 140, 142, 144, 145 ; of 
printing ink vehicles, 71. 

Deodorisation of wood oil, 138. 

Deposition tank for oil clarifying, 54. 

Diglycerides, 53. 

Dipierocarpus crispalettiSf 4. 

Distillation test for volatile oils in lin- 
seed oil, 110 ; destructive products 
of poppy-seed oil, 141. 

Dolphin oil, 132. 

Driers, 27, 56, 85-93 ; catalytic action of, 
31 ; choice of, 44 ; concentrated, 91, 
92; detection and estimation, 56; 
excess of, injurious eflect of, 81; 
energetic, weak and useless, 30; 
manufacture of, 85, 93 ; patent, 
92. 

— lead, metallic, 33; acetate, normal, 
30, 31, 35, 36, 40, 86, 88, 92 ; acetate, 
basic, 20, 31, 33, 36; borate, 87; car- 
bonate, 27, 31, 34, 86 ; chloride, 37 ; 
linoleate, 25, 27, 28, 31, 32, 33, 34, 
87, 88, 91, 130 ; oxalate, 37 ; oxide 
litharge, 27, 29, 30, 31, 33, 35, 38, 
52, 64, 67, 84, 86, 92, 93 ; oxide, red 
lead, 35, 37, 38, 40, 85, 86, 92 ; per- 
oxide, 37 ;' plumbates of alkaline 
earths, 81 ; rosinate, 87 ; lead, man- 
ganese rosinate, 87; tartrate, 37. 



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INDKX. 



149 



Driers, liquid, 36, 92. 

— manganese, acetate, 37, 62, 88, 89; 

borate, 80, 32, 34, 37, 38, 40, 44, 
46, 46, 66, 88, 89, 90, 92, 126; 
chloride, 90 ; citrate, 37 ; formate, 
37 ; hydrated peroxide, 40, 44, 62 ; 
linoleate, 19, 28, 29, 31, 36, 38, 66 ; 
metallic, 88 ; nitrate, 63, 64 ; ores 
used in making, 46 ; oxide, black, 
27, 31, 46, 46, 62, 66, 88, 89; 
oxalate, 37, 66, 88; manganese 
palmitate, 62 ; resinate, 38, 88, 91 ; 
mangano plumbic borates, 46; 
mangano plumbic rosinates, 87 ; 
mangano plumbic linoleo rosin- 
ates, 87 ; manganese sulphate, 16, 
46, 88, 89. 

— zinc, 46 ; oxide, 46 ; sulphate, 46. 
Drying oils, definition, 1 ; effect of heat 

on, 26. 
Dutch linseed, 6 ; oil, 121. 



E. 



Earth-nut oil. 98, 100, 104, 120, 126. 
East Indian linseed, 6, 119, 121, 129. 
Edge runners for oil-cake grinding, 4. 
Elaidin test, 132, 133. 
Electro-plated tanks for storing high- 

dass oil, 68. 
Elevators, seed in oil crushing, 12. 
ElcBococcat 4. 

Enamelled iron oil-boiling pans, 36, 63. 
Endemann and Paisley's researches on 

borate of manganese, 90. 
Endosperm of linseed, 7. 
Engraving, steel and copper ink for, 69, 

70. 
Episperm of linseed, 7. 
Equivalents of caustic and carbonated 

alkali, 116. 
Exothermal phenomena in oil boiling, 

29. 
Extraction of oil by solvents, 13, 14. 



Fatty acid, free of linseed oil, its im- 
portant function in oil boiling, 28, 
32, 46 ; action of, on spongy lead, 
28 ; on lead plates, estimation of 
(acid value), 79. 

fixed solid percentage of (Hehner's 

value), 79, 133, 142, 144. 

mixed iodine value, 119, 120, 139- 

46. 

saponification value of, 116, 

139-46. 
Ferric oxide in linoleum, 61. 
Ferrous sulphates, 20. 
Fillers, linoleum, 61. 



Filtration of linseed oil, 13. 
Fir-seed oil, 120, 127. 
Fire-boiling of linseed oil, 36-44. 
Fish oils, 94, 96, 97, 100, 102, 103, 106, 
107, 120, 124, 126, 132. 

— drying of, 126. 

— Japanese, 126. 
Flash point test, 104, 106. 
Flax, 4-6. 

Freezing point of oils, 100. 

French (linseed, rape, poppy -seed), 

120. 
Fumes, oil boiling, condensation of, 

43. 
Function of drying oils, 2-4. 
Fused rosinates, 38 ; linoleates, 38. 



Galvanised tanks for storing oil, 14. 
Goyneau's printing ink, 67. 
Grape-seed oil, 4, 100, 120. 
Green vitriol, 20. 
Gunther*s printing ink, 68. 
Gurjun balsam, 134, n. 



H. 

Hartley on colour of oil, 16; on sul- 
phuric acid refining of linseed oil, 
16, 32. 

— and Blenkinsop*s oil-boiling process, 
19, 31. 

Hazel-nut oil, 100, 120. 

Heat, effect of, on linseed oil, 26. 

Hehner's value. See fatty acids, fixed 
solid percentage of. 

Hemp-seed oil, 4, 100, 103, 104, 120, 126, 
132, 139, 140. 

Herring oil, 104. 

Hickory-nut oil, 144. 

Horse-foot oil, 106. 

Hydrogen peroxide, bleaching oils by, 
18 ; bleaching discoloured paint- 
ings by, 86. 

Hypochlorite, blea.ching of, colouring 
principles of oil, 17. 



Illustrations de Ivxe^ ink for, 70. 
Imitation india-rubber, 72-83. 

— leather, 73. 

India-rubber substitutes, 72-88. 
Indian colza, 129. 

— linseed. See East Indian linseed. 

— sesame, 129. 

Indigo, 66, 66, 68 ; carmine, 67. 
Ink, printing, etc. See printing ink, 
108. 



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150 



INDEX. 



Iodine, value of, drying oils, 27 ; hemp- 
seed, 140; lallemantia, 138 ; linseed, 
108, 119-21, 131; poppy, 142; wal- 
nut, 143; wood, 189; mixed fatty 
acids of oils, 119, 120, 189-45 ; mixed 
fatty acids of rubber substitutes, 77 ; 
of non-drying oils, various, 120. 

Ivory black (bone black), 66. 



, Jacketed vessels, steam, seed kettle, 9; 

oil-boiling pans, 48-51. 
Japanese fish oil, 126. 

— wood oil, 4, 134-89. 

— gold size, 93. 
Joints, steam, 86. 
JtLglans regia^ 4, 143. 



Kai'dan-longt 4. 

Kastner's plumbates of alkaline earths 

as driers, 31. 
Kernel of linseed, 7. 
Kettle, steam-heated, 9. 



La Plata linseed oil, 5. 
Lakes in printing ink, 66. 
Lallemantia oil, 188, 134. 
Lead driers. See driers. 
Liebermann Storch reaction, 103, 104. 
Light, influence of, on drying of linseed 
oil, 17. 

coloured, 24. 

Linoleates. See driers. 
Linoleum, manufacture of, 57-61. 
Linseed oil : — 
Absorption of bromine by, 122, 123. 

— chlorine, 74 et seq, 

— iodine, 79, 80, 117-21. 

— oxygen, etc., tests for amount of : — 

Bishop's, 127-30. 
Gasselman's, 125. 
Fahrion's, 131. 
Livache's, 126, 126. 
Mulder's, 124, 125. 
Weger's, 126, 127. 

adulteration of, tests for : — 

Absorption tests. See absorption, 

etc. 
Acetic anhydride test, 108. 
Acid value, 112. 

Bromine derivatives insoluble, 124. 
Density, 96-98. 
Distillation, steam, for volatile oils, 

110. 
Elaidin test for non-drying oils, 
132, 133. 



Linseed oil — contintted : — 

Flash point for hydrocarbide oils of 

low volatility, 104-106. 
Iodine and bromine value, 117-24. 
Maumen^'s test, 130-82. 
Melting point of fatty acids, 101. 
Polarimetric tests, 109, 110. 
Refraction tests, 106, 109. 
Rosin tests for, 107, 108, 109, 112-14. 
Rosin oil tests for in, 94, 95, 98, 101, 

108, 104, 107, 110, 112, 113, 117, 

122. 
Saponification test for rosin oil and 

mineral oil, 112. 

— value, 114-17. 
Solidification point of, 98-101. 

— of its fatty acids, 101. 
Sulphuric acid spot test, 101. 
Smell test, 94. 

Taste test, 94. 

Tetrabromide of tin test, 103. 
ageing or prolonged storing of, 

26 et seq. 
air deprived of its oxygen by dry- 
ing off, 1, 2. 
bleaching, refining and clarifying 

raw, 16 et seq, 

boiling of, 85-56, 58-61, 63, 69. 

chemical composition of, 22-25. 

chlorophyll of, 16, 17. 

colour of raw, 95 ; boiled, 65, 85, 

96. 

tests, 101-104. 

colouring principles of, 16, 17. 

density of, 95, 98. 

determination of, in linseed, 13, 

14. 

cake, 13, 14. 

diglycerides theory of oil boiling, 

58. 
driers, lead. See driers and 

manganese driers. 

erythrophyll of, 17. 

extraction of, by solvents, 13, 14. 

fatty acids free of, 28, 32, 45, 

112-14. 

— filtration of, 13. 

— foots, 15, 26, 55. 

— iodine values, 108-19, 121, 131. 

— light, influence of, on drying of, 
17. 

Maumend's test, 130-32. 

. — oxidation of, 1, 26, 27, 84, 72-74, 
124-30. 

■ — polarimetric test for, 109, 110. 

■ — refining of. See bleaching, refin- 
ing and clarifying. 

■ — refractometric test for, 106, 109. 

■ — saponification value, 114-17. 

- — smell of, 94. 
• — solidification test for, 99-101. 

- — substitutes, 4, 35. 

- — taste of, 94. 
. — tetrabromide of tin test, 108. 



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INDEX. 



151 



Linseed oil, crushing and extraction of, 7, 
15 ; botanical and chemical control, 
13, 14 ; cake moulding machine, 8, 
9, 10, 11 ; cake paring machine, 10, 
11 ; cake plates and brand stamp- 
ing, 9 ; conveyors (seed), 8 ; ele- 
vators, 8, 12, 13 ; filter press, 13 ; 
extraction by solvents verstcs, 13. 

— meal, non-oleaginous as cattle food, 
13. 



M. 

Machinery oil boiling, 35-61. 
Magnesia calcined in refining, 16. 
Magnesium rosinate in linoleum, 61. 
Maize oil, 4. See com oil. 
Manganese oxides and salts. See driers, 

manganese. 
Maumene's test, 130-32. 
Melting point of mixed fatty acids, 139, 

140, 141, 142, 144. 
Menhaden oil, 126, 132. 
Mineral oil, insolubility in glacial acetic 

acid, 112. 
Minium. See red lead. 
Molecular weight, mean, of mixed fatty 

acids of oils, 140, 141, 144. 
Moulding machine, oil-cake, 8. 



N. 

Naphtha. See benzene. 
Neatsfoot oil, 100, 125. 
Newspaper printing ink, 67, 68. 
Niger-seed oil, 132. 
Nitric acid, l2, 64, 68. 
Nitro-naphthalene in deblooming, 95. 



Ochre, yellow, 66. 

Oil-cake, 10, 11 ; mill, 12 ; cake press, 9. 

Old tanked oil, 15. 

Olive oil, 98, 100, 104, 120, 124, 126, 127, 

129, 131, 132. 
Organoleptic methods of testing oils, 94, 

96. 
Oxidation of linseed oil. See linseed 

oil. 
Ozokerit in printing ink, 70. 
Ozone^bleaching of oils, 18. 



Paint removers, 4 ; vehicles, 4. 

Palm oil, 104, 120; palm-kernel oil, 

104, 127. 
Pans for oil boiling by fire, 36-38, 44 ; 

by steam, 47-61. 



Papaver somniferum^ 4, 140. 
Paraffin oil, 68 ; paraffin wax, 70. 
Parkes' patent for rubber substitutes, 

74. 
Paring ma.chine for oil cakes, 10, 11. 
Parings, oil cake, grinding, 10, 11. 
Patent driers, 91. 
Paulovmie of Japans 4. 
Permanganate of potash in oil refining, 

18. 
Petroleum spirit, 110, 111. 
Pistachio oil (pea-nut). See arachis. 
Plumbates of alkaline earths as driers, 

81. 
Polarimetrio test for oils, 109, 110. 

rosin oil, 110. 

Polymerisation theory of oil boiling, 86, 

63. 
Poppy-seed oil, 4, 129, 140, 142. 
Potash soaps in linoleate and rosinate 

manufacture, 87, 90, 91. 
Potassium bichromate in oil refining, 19, 
20 ; oil boiling, 64. 

— carbonates in oil refining, 20. 
Pratt's printing ink, 66. 
Precipitated lead as a drier, 33. 

— linoleates, 87, 88, 90, 91. 

— resinates, 91. 

— rosinates, 87, 91. 
Presses, hydraulic, 9, 12. 

Printing ink, asphaltum in, 70 ; blacks, 
65, 66, 70 ; blood black in, 70 ; 
blue black inks, 65 ; blues, 66- 
70 ; camauba wax, 70 ; copper 
plate engraving, ink for, 60; 
cork black, 70 ; drying oil for, 
64, 65, 67, 68, 69 ; earth mineral 
colours unsuitable, 66 ; fish oil, 
68 ; free fatty acids in vehicles, 
71 ; density of, 71 ; Goyneau's 
ink, 67 ; green pigments for, 
66; Gunther's ink, 68; huile 
forte, 64, 70; illustrations, ink 
for, 70 ; indigo, 68 ; indigo car- 
mine, 67 ; iodine, value of, 71 ; 
ivory black, 70; lamp black, 
66 ; mean combining, weight of, 
71 ; melting point of, 71 ; news- 
paper ink, 68 ; nitric acid in oil 
refining for, 63-66, 69-70 ; olein, 
use of in, 67 ; palmitic acid, 
elimination of from, 63 ; pan, 
size and shape of for oil boiling, 
63 ; paraffin oil, use of in, 68 ; 
paraffin wax, use of in, 70 ; pro- 
perties of, 63-66 ; Prussian blue 
m, 66, 67, 68, 70 ; Pratt's vehicle 
for, 69; refining oil for, 62; 
rosin, use of in, 66, 67, 68, 69 ; 
rosin oil, 62-70; sap, value of, 
71 ; soap, use of in, 65, 67, 69, 
70 ; solidifying, point of, 71 ; 
stearic acid in, 70; steel en- 
graving, ink for, 60; stringing 



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162 



INDEX. 



test for, 63 ; sulphuric acid in 
oil refining for testing, 65 ; 
thickened turpentine, 69; ve- 
hicle for, thin, 64, 68-70 ; density 
of, 71 ; free acid in, 71 ; sap 
value, 71. 

Printing ink, medium, 64, 68, 70 ; thick, 
64, 68-70. 

oxidised acids, 71. 

Paris violet, in, 70 ; Villon's en- 
graving ink, 70. 

Prussian blue in printing ink, 64, 66, 66, 
67, 70. 

Pumps, hydraulic pressure, 9, 10, 13. 

— used in oil oxidation, 58. 



Qualitative tests for ash (driers) of boiled 

oil, 58. 
Quantitative analysis of ash (driers) of 

boiled oil, 58. 



B. 



Rape oil, 81, 100, 104, 120, 124, 125-27, 

131. See colza. 
Ravison oil, 103, 107. 
Red lead in oil boiling, 31 ; oil refining, 

21. See lead driers. 
Refraction of oils, 106-109. 
Renard's test for rosin oil, 103. 
RidntLS communis, 4. 
Riga linseed, 5. 
Rolls in linseed crushing, 8. 
Rosin, acid value, 113 ; iodine value, 
117; in linoleum, 61; in linseed 
oil, 113, 117, 122, 123 ; in printing 
ink, 67-69. 
— oil, detection of, 95, 97, 98, 102, 103, 
107, 108, 109, 110, 112-17. 

colour tests, 101-104. 

deblooming, 95. 

Liebermann-Storch test for, 103, 

104. 

Renard's test for, 103. 

saponification test for, 112. 

^ sulphuric acid spot test, 101. 

Rosinate of magnesia in linoleum manu- 
facture, 61, 
Rosinates of lead and manganese. See 

driers. 
Rosin soap, 65, 67, 69, 70. 
Rotary machine, printing nk for, 66. 



S. 

Safflower-seed oil, 4. 
Saponification value, 114-7 
Seal oil, 120, 132. 
Senegal sesamum, 129. 



Sesame oil, 100, 104, 126, 129, 131. 

Shark liver oil, 124. 

Sienna in printing ink, 66. 

Skate oil, 103. 

Smell of linseed, rosin and fish oils, 

94. 
Soap, rosin, printing ink, 65-70. 

— yellow, in printing ink, 65-70. 
Soda, caustic, in oil refining, .10; car- 
bonate, 20 ; peroxide, 18. 

Soja-bean oil, 132. 

Solidification point of linseed and other 

oils, 100. 
Solidified linseed oil, 61. 
Solvents, extraction of oil by, 13, 14. 

— for driers, 34. 
" Stand " oil, 127. 

Steel engraving, ink for, 69-71. 
Storch-Liebermann test for rosin oil,103. 
Storer's oil boiling process, 59. 
Storing of oil, influence of, on drying, 
14. 

methods of, 13, 14, 16, 26, 54, 58. 

St. Petersburg linseed oil, 119. 
Strontium plumbate as a drier, 31. 
Substitutes, linseed oil, 3, 4. 
Sulphur in rubber substitutes, 76-83. 

— chloride in rubber substitutes, 74-83. 
Sunflower oil, 100, 104, 125, 132. 
Sunlight, influence of, on bleaching of 

oil, 17. 
Surface, influence of, on rapidity of dry- 
ing, 29. 



T. 

Tannic acid in oil refining, 16 ; in print- 
ing ink lake making, 66. 

Taste test for linseed oil, 94. 

Terebine, 34, 92. 

Th^nard's process, 15. 

Thickening of oils by oxidation, 56. 

Thorpe's experiments on driers, 36, 37. 

Tin in lead used for lead-plated tanks 
and drums, etc., prevents darkening 
of oils, etc., 58. 

Tint printing ink vehicle, 71. 

Turpentine, refractive index of, 107. 

— estimation of, in linseed oil, 110. 



Ultramarine inadmissible in printing 

ink, 66. 
Umber in printing ink, 66. 



Variations in density, etc., of linseed oil, 

cause of, 96, 97. 
Vehicle, definition of, 2-4. 



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INDEX. 



133 



Vehicles, drying oils as paint and var- 
nish, 2-4. 
— for printing ink, 62-71. 
Vermilion and vermilionette in printing 

ink, 66. 
Vincent's oil boiling process, 36. 
Virgin walnut oil, 143. 
Volatile oils, detection of, in linseed oil, 

2, 110, 111. 
Vulcanised oils, 74 et seq. 



W. 

Walnut oil, 4, 100, 103, 106, 107, 109, 
120, 126, 126, 129, 131, 132, 143-45. 

Walton's oil oxidising process, 58. 

Weather and drying oils, 4. 

Whale oil, 100, 102, 104, 106, 120, 124, 
132. 



White lead in oil boiling, 31. 
— rubber substitutes, 74 et s< 
Wine lees, black, 70. 
Wood oil, 4, 134-39. 



Xanthophyll, 16. 



Y. 



Yellow, chrome, 66 ; soap, 68-70. 



Zinc sulphate in oil boiling, 31. 
— oxide in oil boiling, 31. 



THE ABERDEEN UNIVBRSITi^ PRESS LIMITED, 

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_ OF _ 

Special iDeednieal J3ooks 



FOR 



Manufacturers, Technical Students and 
Workers, Schools, Colleges, etc. 

BY EXPERT WRITERS 



PAOB 

Agricultural Chemistry ... 10 
Air, Industrial Use of ... 12 
Alum and its Sulphates ... 9 

Ammonia 9 

Aniline Colours S 

Animal Fats 6 

Anti-corrosive Paints ... 4 
Architecture, Terms in ... 29 
Architectural Pottery ... IS 

Artificial Perfumes 7 

Balsams 10 

Bibliography 32 

Bleaching 23 

Bleaching Agents 28 

Bone Products 8 

Bookbinding 31 

Brick-making ... 14, 15 

Burnishing Brass 27 

Carpet Yarn Printing ... 21 

Casein 4 

Celluloid 31 

Ceramic Books ... 14, 15, 16 

Charcoal 9 

Chemical Essays 9 

Chemistry of Pottery ... 16 
Chemistry of Dye-stuffs ... 22 

Clay Analysis 16 

Coal-dust Firing 26 

Colour Matching 22 

Colliery Recovery Work ... 25 
Colour-mixing for Dyers ... 22 

Colour Theory 22 

Combing Machines 24 

Compounding Oils 6 

Coodensing Apparatus ... 26 

Cosmetics 8 

Cotton Dyeing 22 

Cotton Spinnmg 24 

Damask Weaving 21 

Dampness in Buildings ... 29 

Decorators' Books 28 

Decorative Texfles . ... 20 

Dental Metallurgy 25 

Dictionary of Paint Materials 2 

Drying Otis 5 

Drying with Air 12 

Dyeing Marble 80 

I^eing Woollen Fabrics ... 22 

Dyers^ Materials 22 

Dye-stuffs 23 

Electric Wiring 27 

Electricity in Collieries ... 25 

Enamelling Metal 18 

Enamels 18 

Engraving 81 

Essential Oils 7 



INDEX TO SUBJECTS. 

PAGE 

Extracts, Wood 29 

Evaporating Apparatus ... 26 
External Plumbing ... 27 

Fats 5,6 

Faults in Woollen Goods... 21 

Flax Spinning 24 

Fruit Preserving SO 

Gas Firing 26 

Glass-making Recipes ... 16 

Glass Painting 17 

Glue Making and Testing ... 8 

Greases 5 

Hat Manufacturing ... 20 

Hemp Spinning 24 

History of Staffs Potteries 16 

Hops 28 

Hot-water Supply 28 

How to make a Woollen Mill 

Pay 21 

India-rubber 18 

Industrial Alcohol 10 

Inks ... 8,11 

Iron-corrosion .'.. ... 4 

Iron, Science of 26 

Japanning ... 28 

Jute Spinning 24 

Lace-Making 20 

Lacquering 27 

Lake Pigments 2 

Lead and its Compounds... 1 1 

Leather Industry 13 

Leather-working Materials 14 

Libraries 32 

Lithography 81 

Lubricants 5,6 

Manures 8, 10 

Meat Preserving SO 

Mineral Pigments 3 

Mineral Waxes 6 

Mine Ventilation 25 

Mine Haulage 25 

Mining, Electricity ... 25 

Needlework 20 

Oil and Colour Recipes ... 8 

Oil Boiling 5 

Oil Merchants' Mtuiual ... 6 

Oils 5 

Ozone, Industrial Use of... 12 
Paint Manufacture ... 2 

Paint Materials 3 

Paint-material Testing ... 4 

Paint Mixing 28 

Paper-Mill Chemistry ... 17 

Paper-pulp Dyeing 17 

Petroleum 6 



PAOB 

Pigments, Chemistry of ... 2 



Plumbers' Work 
Porcelain Painting 
Pottery Clays 
Pottery Decorating 
Pottery Manufacture 
Pottery Marks 
Power-loom Weaving 
Preserved Foods 



, 27 

, 17 

, 16^ 

15 

14 

. 16 

20 

30 



Printers' Ready Reckoner 81 

Printing Inks 8 

Recipes for Oilmen, etc. ... 8 

Resins ... 10 

Risks of Occupations ... 12 
Riveting China, etc. ... 16 
Sanitary Plumbing ... 27 

Scheele*s Essays 9 

Sealing Waxes II 

Silk Dyeing 22 

Silk Throwing 18 

Smoke Prevention 28 

Soaps 7 

Spinning S\ 

Staining Marble, and Bone 80 

Steam Drving 19 

Sugar Refining 82 

Steel Hardening 28 

Sweetmeate 80 

Tanning Extracta 2l» 

Technical Schools, Htuid> 

book to the 82 

Terra-cotta 16 

Testing Paint Materiab ... 4 

Testing Yams 20 

Textile Fabrics ... 19,20 
Textile Fibres ... 20, 24 

Textile Materials 20 

Timber 29 

Varnishes 8 

Vegetable Fats 7 

Vegetable Preserving ... 80 

Waste Utilisation 11 

Water, Industrial Use ... 12 
Water^proofing Fabrics ... 21 

Waxes 6 

Weaving Calculations ... 21 
White Lead and Zinc ... 4 

Wood Distillation 29 

Wood Waste UtilisatkMi... 29 



Wood-Dyeing 
Wool-Dyeing 
Writing Inks 
XRay Work 
Yam Testing 
Zina Whit^ainta 



, 80 
22, 2S 
... 11 
... 18 



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8 Broadway, Ludgate Hill, 

London, E.G. , 

Mapben*, BMk UM. lUatfnphle Addfoa, •< Prlataria^ London 30 [^ 



Paints, Colours and Printing 
Inks. 

THE CHEMISTRY OP PIGMENTS. By Ernest J. Parry, 
B.Sc. (Lond.), F.I.C., F.C.S., and J. H. Costb, F.I.C, F.C.S. Demy 
8vo. Five Illustrations. 285 pp. Price 10s. 6d. net. (Post free, 
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Contents. 

lotroductory. Light— White Light— The Spectrum— The Invisible Spectrum— Normal 
Spectrum — Simple Nature of Pure Spectral Colour— The Recomposition of White Light — 
Primary and Complementary Colours— Coloured Bodies— Absorption Spectra — The Appil- 
catioo of PIflfinents. Uses of Pigments: Artistic, Decorative, Protective— Methods of 
Application of Pigments : Pastels and Crayons, Water Colour, Tempera Painting, Fresco, 
Encaustic Painting, Oil-colour Painting, Keramic Art, Enamel, Stained and Painted Glass, 
Mosaic— InofffMlIc PlnnMlts. White Lead— Zinc White— Enamel White— Whitening — 
Red Lead — Litharge — Vermilion— Royal Scarlet — ^The Chromium Greens — Chromates of Lead, 
Zinc, Silver and Mercurv— Brunswick Green — ^The Ochres — Indian Red — Venetian Red — 
Siennas and Umbers — Light Red — Cappagh Brown— Red Oxides — Mars Colours — Terre Verte 
— Prussian Brown — Cobalt Colours — Coeruleum — Smalt — Copper Pigments — Malachite — 
Bremen Green — Scheele's Green — Emerald Green — Verdigris — Brunswick Green — Non- 



arsenical Greens — Copper Blues — Ultramarine — Carbon Pigments — Ivory Black — Lamp Black 
— Bistre — Naples Yellow — Arsenic Sulphides : Orpiment, Realgar— Cadmium Yellow — 
Vandyck Brown — Orgranic Pigments. Prussian Blue — Natural Lakes — Cochineal — Carmine 



— Crimson — Lac Dye — Scarlet — Madder — Alizarin — Campeachy— Quercitron — Rhamnus — 
Brazil Wood— Alkanet- Santal Wood— Archil— Coal-tar Lakes— KecT Lakes— Alizarin Com- 
ipounds — Orange and Yellow Lakes— Green and Blue Lakes— Indigo— Dragon's Blood — 
•Gamboge — Sepia — Indian Yellow, Puree — Bitumen, Asphaltum, Mummy — Index. 

THE MANUFACTURE OP PAINT. A Practical Handbook 
for Paint Manufacturers, Merchants and Painters. By J. Cruickshank 
Smith, B.Sc. Demy 8vo. 200 pp. Sixty Illustrations and One Lar^e 
Diagram. Price 7s. 6d. net. (Post free, 78. lOd. home ; 8s. abroad.) 

Contents. 

Preparation of Raw Material— Storing of Raw Material— Testing and Valuation of Raw 
Material— Paint Plant and Machinery— The Grinding of White Lead— Grinding of White 
Zinc — Grinding of other White Pigments — Grinding of Oxide Paints — Grinding of Staining 
Colours — Grinding of Black Paints — Grinding of Chemical Colours — Yellows— Grinding of 
Chemical Colours — Blues — Grinding Greens — Grinding Reds — Grinding Lakes— Grinding 
Colours in Water— Grinding Colours m Turpentine— The Uses of Paint— Testing and Matching 
Paints— Economic Considerations — Index. 

DICTIONARY OF CHEMICALS AND RAW PRO- 
DUCTS USED IN THE MANUFACTURE OF 
PAINTS, COLOURS, VARNISHES AND ALLIED 
PREPARATIONS. By George H. Hurst, F.C.S. Demy 
8vo. 380 pp. Price 7s. 6d. net. (Post free, 8s. home ; 8s. 6d. abroad.) 

THE MANUFACTURE OF LAKE PIGMENTS FROM 
ARTIFICIAL COLOURS. By Francis H. Jennison, 
F.I.C, F.C.S. Sixteen Coloured Plates, showing: Specimens of 
ElfiTlity-nlne Colours, specially prepared from the Recipes grhren 
In the Book. 136 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 
7s. lOd. home; 8s. abroad.) 

contents. 

The Groups of the Artificial Colouring Matters— The Nature and Manipulation of Artificial 
Colours — Lake-forming Bodies for Add Colours— Lake-forming Bodies' Basic Colours — Lake 
Bases— The Principles of Lake Formation- Red Lakes— Orange, Yellow, Green, Blue, Violet 
and Black Lakes— The Production of Insoluble Azo Colours in the Form of Pi|(ment»— The 
General Properties of L«ke8 Produced from Artificial Colours— Washing, Filtering and Fin- 
tshing— Matching and Testing Lake Pigments— Index. 



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THE MANUFACTURE OF MINERAL AND LAKE 
PIGMENTS. Containing Directions for the Manufacture 
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and Painters. By Dr. Josef Bersch. Translated by A. C. WrighTj 
M.A. (Oxon.), B.Sc. (Lond.). Forty-three Illustrations. 476 pp., demy 
8vo. Price 12s. 6d. net. (Post free, 13s. home ; 13s. 6d. abroad.) 

RECIPES FOR THE COLOUR, PAINT, VARNISH, OIL, 
SOAP AND DRYSALTERY TRADES. Compiled by 
An Analytical Chemist. 350 pp. DemySvo. Pricc7s.6d.net. (Post 
free, 8s. home; 8s. 3d. abroad.) 

OIL COLOURS AND PRINTERS' INKS. By Louis 
Edgar Andi^s. Translated from the German. 215 pp. Crown 8vo. 
56 Illustrations. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 
Contents. 

Linseed Oil — Poppy Oil — Mechanical Purification of Linseed Oil — Chemical Purification of 
Linseed Oil— Bleaching Linseed Oil— Oxidizing Agents for Boiling Linseed Oil — Theory of 
Oil Boiling — Manufacture of Boiled Oil — Adulterations of Boiled Oil — r^hinese DQring Oil and 
Other Specialities — Pigments for House and Artistic Painting and Inks — Pigment for 
Printers' Black Inks — Substitutes for Lampblack — Machinery for Colour Grinding and 
Rubbing — Machines for mixing Pigments with the Vehicle — Paint Mills — Manufacture of 
House Oil Paints — Ship Paints — Luminous Paint — Artists' Colours — Printers' Inks: — 
VEHICLES— Printers' Inks :— PIGMENTS and MANUFACTURE— Index. 

MODERN PRINTING INKS. A Practical Handbook for 

Printing Ink Manufacturers and Printers. By Alfred Seymour. 

Demy 8vo. Six Illustrations. 90 pages. Price 5s. net. (Post free, 

5s. 4d. home ; 5s.' 6d. abroad.) [y^^^ published. 

Contents. 

Introduction. — Division of Labour — A Separate Industry — Choice of Materials — Skilful 
Manipulation — Some Important Factors — The Medium — Ink and Colour Mixing — A Justifica- 
tion. Linseed Oil. — Extraction of the Oil — Classification — Mechanical Purification — 
Adulteration — Boiled Oil— Preparation of Boiled Oil — An Alternative Process. Vamisli. — 
A Vehicle and Essential Component — A Reference to Lithography — Baltic Oil — Preparation 
of Varnish — The Modern Method — ^An Old Argument — Letterpress Varnish — A Cheaper. 
Medium— A Suggestive Recipe — Fire Risks — Gradations of Varnish. Dry Colours. — A 
Recommendation — An Endless Variety of Materials — Earth Colours — Mineral Colours — 
Substrates — Toning Earth Colours — Physical Characteristics-^Colouring Power — Brilliance — 
Purity of Tone— Permanence. Dry Colours— Blaclcs, Wliltes, Yellows— Lampblack- 
Process of Manufacture — Calcination— Carbon Black— Acetylene Black — ^A Simple Test — Lead 
and Zinc Whites — White Egrth Colours— Yellows — Yellow Ochres — Mineral Yellows. Dry 
Colours — Reds, Browns. — Classification of Reds — Genuine Vermilions — Preparation — 
Imitation Vermilions — Umber, Raw and Burnt— Sienna, Raw and Burnt. Blues, Greens. — 
Ultramarine Blue— A Useful Tint— Other Similar Blues— Cobalt Blues— Prussian— Chinese 
and Bronze Blues — A Test for Purity — Greens — Compound Greens— Mine ral Greens. Lakes. 
— Characteristics — Lake Derivatives — A Point of Importance — Red Lakes — Madder — 
Cochineal and Carmine — Brazil Wood— Alizarine a Coaltar Derivative — Yellow Lakes — Blue- 
Lakes— Green Lakes. Tlie Qrlndinff of Printing Inlcs.— Ink-grinding Machinery— Ink- 
grinding Mill — A Novel Machine — Hand Grinding — Treatment of Gritty Colours— A Question 
of Proportion— Approximate Calculation — Soap — Saturation — Friction Heat — Consistent 
Grinding. Inic and Colour Mixing;.— A Necessary Acquisition— Ink Mixing Defined— Mixed 
Green Inks — Mixed Brown Inks — ^Tints — Ink Mixing — Lithographic Inks — C haracteristics of 
Yellows— Mixing Vermilion— Ultramarine and Other Blues— Bronze, Prussian and Chinese 
Blues — Working Consistency— Reducing Medium — Letterpress Inks — Gloss Inks — Three- 
colour Inks— Ink-mixing Machine. The Characteristics of Some Pr nting Processes.— 
A Supplementary Discussion — Letterpress Inks — ^Three-colour Printing — Lithographic Printing 
Inks— An Important Feature— Suggestive Points— Tinplate Printing. Driers.— A Valuable 
Auxiliaiy— Energetic Drying Ioks--The Theory of Diying— Liquid Driers— Terebene— Paste 
Driers — Letterpress Driers — Powder Driers — ^Turpentme as a Drier. Bronze Powders and 
Bronzing.— A Brief Justification- Bronze Printing Inks— Bronze Powders— The Process of 
Manufacture — Preparation of the Leaf— Grinding and Grading — Bronzin g Mediums — Requisite 
Qualities— Wax Varnish. **Thinirs Worth Knowing." — A Record of Notes and 
Bxperiences — I ndex. 

(See also Writing Inks^ p. ii.) 

THBEE HUNDRED SHADES AND HOW TO MIX 

THEM. For Architects, Decorators and Painters. 

{See page 28.) 



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CASEIN. By Robert Scherbr. Translated from the German 
by Chas. Salter. Demy 8vo. Illustrated. 160 pp. Price 7s. 6d. 
net. (Post free, 7s. lOd. home ; 8s. abroad.) 
Contents. 
Casein : Its Origin, Preparation and Properties. Various Methods of Preparlnar 
Casein. Composition and Properties of Casein. Casein Paints.— " Marble-Lime ^* 
Colour for Outside Work— Casein Enamel Paint— Casein Pafade Paint — Cold- Water Paint in 
Powder Form— Kistory's Recipe for Casein Paint and Varnish— Pure Casein Paints for Walls, 
etc.-^Casein Paints for Woodwork and Iron — Casein- Silicate Paints — Milk Paints — Casein- 
Silicate Paint Recipe»— Trojel's Boiled Oil Substitute— Cal««omine Wash— Quick- Drying 
Casein Paint— Boiled Oil Substitute— Ring's Cold-Water Paint— Formolactin— Waterproof 
Paint for Playing Cards— Casein Colour Lake -Casein-Cement Paint. The Technics of 
Casein Painting. Casein Adheslves and Putties.— Casein Olue in Plates or Flakes — 
Jeromin's Casein Adhesive — Hall's Casein Olue — Waterproof Glue — Liquid Casein Olue — 
Casein and Borax Olue — Solid Casein Adhesive — Casein Solution — Olue Powder — Casein 
Putties— Wmhable Cement for Deal Boards— Wenk's Casein Cement— Casein and Lime Cement 
—"Pitch Barm"— Casein Stopping— Casein Cement for Stone. The Preparation of 
Plastic Masses from Casein. — Imitation Ivory— Anti-Radiation and Anti-Corrosive Com- 
position — Dickmaon's Covering for Floors and Walls — Imitation Linoleum — Imitation 
Leather — Imitation Bone — Plastic Mass of Keratin and Casein — Insulating Mass — Plastic 
Casein Masses — Horny Casein Mass — Plastic Mass from Celluloid — Casein Cellulose Compo- 
-sition — Fireproof Cellulose Substitute — Nitrocellulose and Casein Composition — Pranquet's 
•Celluloid Substitute— Galalith. Uses of Casein In the Textile Industry, for Finishing 
•Colour Printing, etc. — Caseogum — "Olutin" — Casein Dressing for Lmen and Cotton 
^Fabrics — Printing Colour with Metallic Lustre — Process for Softening, Sizing and Loading — 
Fixing Casein and Other Albuminoids on the Fibre — Fixing Insoluble Colouring Matters — 
Waterproofing and Softening Dressing— Casein for Meroerismg Crftpe — Fixing Zinc White on 
•Cotton with Pormaldehyde--Casein- Magnesia — Casein Medium for Calico Printing — Loading 
:Silk. Casein Foodstuffs.— Casein Food— Synthetic Milk— Milk Food— Emulsiflable Casein 
—Casein Phosphate for Baking — Making Bread, Low in Carbohydrates, from Flour and Curd 
—Preparing Soluble Casein Compounds with Citrates— Casein Food. Sundry Applications 
•of Casein. 

SIMPLE METHODS FOR TESTING PAINTERS' 
MATERIALS. By A. C. Wrioht, M.A. (Oxon.), B.Sc, 
(Lend.). Crown 8vo. 160 pp. Price 5s. net. (Post free, 5s. 3d. 
home ; 5s. 6d. abroad.) 

IRON - CORROSION, ANTI- FOULING AND ANTI- 
CORROSIVE PAINTS. Translated from the German of 
Louis Edoar ANDiss. Sixty-two Illustrations. 275 pp. Demy Svo. 
Price 10s. 6d. net. (Post free, 10s. lOd. home; lis. 3d. abroad.) 
Contents. 

Iron-rust and its Formation — Protection from Rusting by Paint — Grounding the Iron with 
Linseed Oil, etc. — ^Testing Paints — Use of Tar for Paintmg on Iron — ^Anti-corrosive PaintSr— 
Linseed Varnish — Chinese Wood Oil — Lead Pigments — Iron Pigments — Artificial Iron Oxides 
— Carbon — Preparation of Anti-corrosive Paints — Results of Examination of Several Anti- 
corrosive Paints — Paints for Ship's Bottoms — Anti-fouling Compositions — Various Anti-cor- 
rosive and Ship's Paints — Official Standard Specifications for Ironwork Paints — Index. 

THE TESTING AND VALUATION OF RAW MATE- 
RIALS USED IN PAINT AND COLOUR MANU- 
FACTURE. By M. W. Jones, F.C.S. A Book for the 
Laboratories of Colour Works. 88 pp. Crown 8vo. Price 5s. net. 
(Post free, 5s. 3d. home and abroad.) 

THE MANUFACTURE AND COMPARATIVE MERITS 
OF WHITE LEAD AND ZINC WHITE PAINTS. By 

G. Petit, Civil Engineer, etc. Translated from the French. Crown Svo. 
100 pp. Price 4s. net. (Post free, 4s. 3d. home ; 4s. 4d. abroad.) 
Contents. 

Chapters I., The Fundamental Principles of Painting in Oil. II., The DifFerent Varieties of 
White Leads— The Dutch Process— Onnding White Lead in Oil. III., Other Processes of 
Manufacturing White Lead. IV., White Lead Substitutes— Sophistication of White Lead- 
Analysis of White Lead. V., White Lead Paints— Their Merits and Defects. VI., Toxi- 
colc^ of White Lead — Hygienic Measures in its Manufacture and Use. VII., Zinc White- 
Its Preparation. IX., Zinc White Paint and Zinc White Coatings— Their Merits and DefbcU 



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STUDENTS* HANDBOOK OF PAINTS, COLOXTRS, OILS 
AND VARNISHES. By John Furnell, Crown 8vo. 12 
Illustrations. 96 pp. Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.) 

Varnishes and Drying Oils. 

OIL CRUSHING, REFINING AND BOILING, THE 
MANUFACTURE OF LINOLEUM, PRINTING AND 
LITHOGRAPHIC INKS, AND INDIA-RUBBER 
SUBSTITUTES. By John Geddes McIntosh, Being 
Volume I. of the Second, greatly enlarged, English Edition, in three 
Volumes, of ** The Manufacture of Varnishes and Kindred Industries," 
based on and including the work of Ach. Livache. Demy 8vo. 150 pp. 
29 Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home; 8s. 
abroad.) 

VARNISH MATERIALS AND OIL-VARNISH MAKING. 

By J. G. McIntosh. Being Vol. II. of " The Manufacture of Varnishes 
and Kindred Industries". Demy Svo. 70 Illustrations. 220 pp. 
Price 10s. 6d. net. (Post free, 10s. lOd. home ; lis. 3d. abroad.) 
Contents. 

Chapter I., Introduction. II., Amber and Amber Oil Varnishes. III., Copal, etc. IV., 
Resins— Assorting, Cleaning and Fusing. V., Asphaltum, Coal-Tar, Pitch, Rubber, etc. VI., 
Oil-Varnish Making— General Instructions. VII., Copal Oil Varnish. VIII., Rosin Oil Varnish 
— Brunswick Black— Super Black Japan. IX., Testing Varnish — Utilisation of Residues. 

DRYING OILS, BOILED OIL AND SOLID AND 
LIQUID DRIERS. By L. E. Andes. Expressly Written 
for this Series of Special Technical Books, and the Publishers hold 
the Copyright for English and Foreign Editions. Forty-two Illustra- 
tions. 342 pp. Demy Svo. Price 12s. 6d. net. (Post free, 13s. home ; 
13s. 3d. abroad.) 

Contents. 

Properties of the Drying Oils ; Cause of the Drying Property ; Absorption of Oxygen ; 
Behaviour towards Metallic Oxides, etc.— The Properties of and Methods for obtaining the 
Drying Oils — Production of the Drying Oils by Expression and Extraction; Refining and 
Bleaching; Oil Cakes and Meal; The Refining and Bleaching of the Drying Oils; The 
Bleaching of Linseed Oil— The Manufacture of Boiled Oil ; The Preparation of Drying Oils 
-for Use in the Grinding of Paints and Artists' Colours and in the Manufacture of Varnishes 
bv Heating over a Fire or by Steam, by the Cold Process, by the Action of Air, and by Means 
of the Electric Current ; The Driers used in Boiling Linseed Oil ; The Manufacture of Boiled 
Oil and the Apparatus therefor; Livache's Process for Preparing a Good Drying Oil and its 
Practical Application— The Preparation of Varnishes for Letterpress, Lithographic and Copper- 
plate Printing, for Oilcloth and Waterproof Fabrics ; The Manufacture of Thickened Linseed 
Oil, Burnt Oil, Stand Oil by Fire Heat, Superheated Steam, and by a Current of Air — Behaviour 
of the Drying Oils and Boiled Oils towards Atmospheric Influences, Water, Acids and Alkalies 
^Boiled Oil Substitutes— I'he Manufacture of Solid and Liquid Driers from Linseed Oil and 
Rosin; Linolic Acid Compounds of the Driers — ^The Adulteration and Examination of the 
Drying Oils and Boiled Oil. 

Oils, Fats, Waxes, Greases, 
Petroleum. 

IiUBRICATING OILS, FATS AND GRITASES : Their 
Origin, Preparation, Properties, Uses and Analyses. A Handbook for 
Oil Manufacturers, Refiners and Merchants, and the Oil and Pat 
Industry in General. By Georob H. Hurst, P.C.S. Second Revised 
and Enlarged Edition. Sixty-five Illustrations. 317 pp. Demy 8va 
Price 10s. 6d. net. (Post free, lis. home; lis. 3d. abroad.) 
Contents. 
Introductory— Hydrocarbon Oils— Scotch Shale Olla—Petroleam— Vegetable and 

Animal Oils— Testing and Adulteration of Oils— Lttbricatln^Qreases^Labrication — 

Appendices— Index. 



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6 ♦ 

TECHNOLOGY OF PETROLEUM: Oil Fields of the 
World — ^Their History, Geography and Geology — Annual Production 
and Development — Oil-well Drilling — Transport. By Henry Neu- 
BEROBR and Henry Noalhat. Translated from the French by J. G. 
McIntosh. 550 pp. 153 Illustrations. 26 Plates. Super Royal 8vo. 
Price 2l8. net. (Post free, 21s. 9d. home ; 2ds. 6d. abroad.) 

Contents, 
study of the Petroliferous Strata. 

Excavations— Hand Excavation or Hand Digging of Oil Wells. 
Methods of Boring. 

Accidents— Boring Accidents— Methods of preventing them— Methods of remedying then* 
— Explosives and the use of the " Torpedo " Levigation — Storing and Transport of Petroleum 
— General Advice — Prospecting, Management and carrying on of Petroleum Boring Operations. 

Qeneral Data— Customary Formulas— Memento. Practical Part. General Data 
bearing on Petroleum — Glossary of Technical Terms used in the Petroleum Industry— Copious 
Index. 

MINERAL WAXES : Their Preparation and Uses. By 
Rudolf Gregorius. Translated from the German. Crown 8vo. 250 
pp. 32 Illustrations. Price 6s. net. (Post free, 6s. 4d. home ; 
6s. 6d. abroad.) 

Contents. 
Ozoicerite—Ceresine— Paraffin— Refining: Paraffin— Mineral Wax— Appliances for 
Bxtractinff, Distilllns: and Refininor Ozokerite— Uses of Ceresine, Paraffin and 
Mineral Waxes— Paint and Varnish Removers— Leather and Piston-Rod Qreases— 
Recipes for Silk, Cotton and Linen Dressings— Candles. 

THE PRACTICAL COMPOUNDING OF OILS, TAL- 
LOW AND GREASE FOR LUBRICATION, ETC. 

By An Expert Oil Refiner. Second Edition. 100 pp. Demy 8vo. 
Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.) 
Contents. 

Introductory Remarks on the General Nomenclature of Oils, Tallow and Greases 
suitable for Lubrication ~ Hydrocarbon Oils— Animal and Fish Oils — Compound 
Oils— Vesretable Oils— Lamp Oils— Engine Tallow, Solidified Oils and Petroleum 
Jelly— Machinery Qreases: Loco and Anti-frictlon— Clarifying and Utilisation 
of Waste Fats, Oils, Tank Bottoms, Drainlnsfs of Barrels and Drums, Plcktafffr 
Up, Dregs, etc.— The Plxins: and Cleaning of OU Tanks, etc.— Appendix and 
General Information. 

ANIMAL FATS AND OILS: Their Practical Production, 
Purification and Uses for a great Variety of Purposes. Their Pro- 
perties, Falsification and Examination. Translated &*om the German 
of Louis Edgar And^ss. Sixty-two Illustrations. 240 pp. Second 
Edition, Revised and Enlarged. Demy Svo. Price 10s. 6d. net. 
(Post free, 10s. lOd. home; lis. 3d. abroad.) 

THE MANUFACTURE OF LUBRICANTS, SHOE 
POLISHES AND LEATHER DRESSINGS. By 

Richard Brunner. Translated from the Sixth German Edition by 
Chas. Salter. 10 Illustrations. Crown Svo. 170 pp. Price 7s. 6d. 
net. (Post free, 7s. lOd. home; 8s. abroad.) 

THE OIL MERCHANTS' MANUAL AND OIL TRADE 
READY RECKONER. Compiled by Prank P. Shbrrifp. 
Second Edition Revised and Enlarged. Demy Svo. 214 pp. 1904. 
With Two Sheets of Tables. Price 78. 6d. net. (Post free, 78. lOd. 
home ; Ss. 3d. abroad.) 

contents. 

Trade Terms and Customs— Tables to Ascertain Value of Oil soldjper cwt. or ton — Specifie 
Gravity Table8~Percentai;e Tare Tables— Petroleum Tables— Paraffine and Benzoline Calcu- 
lations—Customary Drafts— Tables for Calculating Allowance for Dirt, Water, eta — Capacity 
of CireulRr Tanks, Tables, etc. etc. 



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VEGETABLE FATS AND OILS: Their Practical Prepara- 
tion, Purification and Employment for Various Purposes, their Proper- 
ties, Adulteration and Examination. Translated from the German of 
Louis Edgar And^ss. Ninety-four Illustrations. 340 pp. Second 
Edition. Demy 8vo. Price 10s. 6d. net. (Post free, lis. home; 
lis. 6d. abroad.) 

EDIBLE FATS AND OILS : Their Composition, Manufacture 
and Analysis. By W. H. Simmons, B.Sc. (Lond.), F.C.S. 

[In preparation. 
The Contents will include the Constitution of Oils and Pats ; Raw Materials ; Bleaching, 
Deodorising and Refining; Butter; Lard; Margarine; Salad Oils; Chocolate Cream; 
Analysis of Raw Materials ; Statistics. 

Essential Oils and Perfumes. 

THE CHEMISTRY OF ESSENTIAL OILS AND ARTI- 

FICIAL PERFUMES. By Ernest J. Parry, B.Sc. 

(Lond.), F.I.C., F.C.S. Second Edition, Revised and Enlarged. 552 pp. 

20 Illustrations. Demy 8vo. Price 12s. 6d. net. (Post free, 138. home ; 

13s. 6d. abroad.) 

Contents. 
Chapter I. The General Properties of Essential Oils. II. Compounds occurrinur In 
essential Oils : (I.) The Terpenes— Sesquiterpenes — Olefinic Terpenes and Sesquiterpenes— 
Pinene— (II.) The Camphor Series— <I II.) The Geraniol and Citronellol Group— The Geraniol 
and Citronellol Series— (IV.) Benzene Compounds : Cymene — Phenols and their Derivatives 
— Phenols with Nine Carbon Atoms — Phenols with Ten Carbon Atoms — Alcohols— Aldehydes 
— Ketones — Acids — (V.) Aliphatic Compounds : Alcohols — Acids — Aldehydes — Sulphur Com- 
pounds—Other Bodies. III. The Preparation of Essential Oils : Expression- Distillation 
—Extraction. IV. The Analysis of Essential Oils : Specific Gravity— Optical Methods : 
(1) Refraction (2) Polarimetry, Melting and Solidifying Points— Boiling Point and Distillation 
—Quantitative Estimations of Constituents— Aldehydes, Ketones and Oils on which a Direct 
Determination can be made. V. Systematic Study of the Essential Oils. VI 
Chemistry of Artificial Perfumes. Appendix I. Table on Constants of the mere 
important Essential Oils. Appendix II. Table of Pharmacopceial Standards. Index.-, 



SoapSe 



SOAPS. A Practical Manual of the Manufacture of Domestic, 
Toilet and other Soaps. By George H. Hurst, F.C.S. 2nd edition. 
990 pp. 66 Illustrations. Price 12s. 6d. net. (Post free, 138. home ; 
138. 6d. abroad.) 

Contents. 
Introductory— Soap-maker's Alkalies— Soap Pats and Oils— Perfumes— Water as 
« Soap Material— Soap Machinery— Technolofify of Soap-maklng^-Qlycerlne in ,Soap 
Lyes— LAyinur out a Soap Factory— Soap Analysis— Appendices. 

TEXTILE SOAPS AND OILS. Handbook on the Prepara- 
tion, Properties and Analysis of the Soaps and Oils used in Textile 
Manufacturing, Dyeing and Printing. By George H. Hurst, F.C.S. 
Crown Svo. 195 pp. 1904. Price 5s. net. (Post free, 5s. 4d. home ; 
5s. 6d. abroad.) 

THE HANDBOOK OF SOAP MANUFACTURE. By 

Wm. H. Simmons, B.Sc. (Lond.), F.C.S. and H. A. Applbton. Demy 
Svo. 160 pp. 27 Illustrations. Price 8s. 6d. net. (Post free, 
8s. lOd. home ; 98. abroad.) 

Contents. 

Deflnltlon of Soap^-Properties^Hydrolysis— Detergent Action. Constitution of Oils 

and Fats, and their Saponification.— Researches of Chevreul and Berthelot— Mixed 

Olycerides— Modem Theories of Saponification— Hydrolysis accelerated by (1) Heat or 

JBIectrlcity. (2) Ferments, Castor-seed Ferment, Steapsin Bmulsin and (3) Chemical 



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contents of *' Handbook of Soap Manufacture"— con/m«e<;. 

Reagents, Sulphuric Add, Twitchell's Reagent, Hydrochloric Acid, Lime, Magnesisi, Zinc 
Oxide, Soda and Potash. Raw Materials used In Soap-making.— Pats and Oils— Waste 
Pats— Patty Acids— Less-known Oils and Fats of Limited Use— Various New Pats and Oils 
Suggested for Soap-making— Rosin — Alkali (Caustic and Carbonated)— Water— Salt Soap- 
stock. Bleaching and Treatment of Raw Materials Intended for Soap-making*. — 
Pain Oil— Cottonseed Oil— Cottonseed " Poots "—Vegetable Oils— Animal Pats— Bone Pat — 
Rosin. Soap- making.— Classification of Soaps— Direct combination of Patty Acids with 
Alkali — Cold Process Soaps — Saponification under Increased or Diminished Pressure — Soft 
Soap-;-Marine Soap— Hydrated Soaps, Smooth and Marbled— Pasting or Saponification — 
Graming Out— Boiling on Strength— Fitting— Curd Soaps— Curd Mottled— Blue and Grey 
Mottled Soaps— Milling Base— Yellow Household Soaps— Resting of Pans and Settling of 
Soap— Utilisation of Nigres— Transparent Soaps— Saponifying Mineral Oil— Electrical Pro- 
duction of Soap. Treatment of Settled Soap.— Cleansing— Crutching— Liquoring of Soaps 
— Pilling— Neutralising, Colouring and Perfuming— Disinfectant Soaps — Framing— Slabbing 
—Barring— Open and Close Piling— Drying— Stamping— Cooling. Toilet, Textile and 
Miscellaneous Soaps.— Toilet Soaps— Cold Process Soaps— Settled Boiled Soaps— Remelted 
Soaps— Milled Soaps — Drying, Milling and Incorporating Colour, Perfumes, or Medicaments 
— Perfumes — Colouring Matter — Neutralising and Super-fatting Material — Compressing — 
Cutting— Textile Soaps— Soaps for Woollen, Cotton and Silk Industries— Patent Textile 
Soaps— Stamping— Medicated Soaps— Ether Soap — Floating Soaps — Shaving Soaps — 
Miscellaneous Soaps. Soap Periumes.— Essential Oils— Source and Preparation— Properties 
—Artificial and Synthetic Perfumes. Glycerine Manufacture and Purification.— Treat- 
ment of Lyes— Evaporation — Crude Glycerine — Distillation — Distilled and Dynamite 
Glycerine— Chemically Pure Glycerine— Animal Charcoal for Decolorisation- Glycerine 
resultant from other methods of Saponification — Yield of Glycerine from Fats and Oils. 
Analysis of Raw Materials, Soap and Glycerine.— Fats and Oils— Alkalies and Alkali 
Salts— Essential Oils— Soap— Lyes— Crude Glycerine. Statistics of the Soap Industry. 
Appendix A.— Comparison of Degrees Twaddell, Beaume and Actual Densities. 
Appendix B.— Comparison of Different Thermometric Scales. Appendix C— Table of 
the Specific Gravities of Solutions of Caustic Soda. Appendix D.— Table of Strength 
of Caustic Potash Solutions at 60° F. Index. 

Gosmetical Preparations. 

COSMETICS : MANUFACTURE, EMPLOYMENT 
AND TESTING OF ALL COSMETIC MATERIALS 
AND COSMETIC SPECIALITIES. Translated 
from the German of Dr. Theodor Koller. Crown 8vo. 262 pp. 
Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 
Contents* 

Purposes and Uses of, and Ingredients used in the Preparation of Cosmetics— Preparation of 
Perfumes by Pressure, Distillation, Maceration, Absorption or Enfleurage, and Extraction 
Methods — Chemical and Animal Products used in the Preparation of Cosmetics — Oils and Fats 
used in the Preparation of Cosmetics— General Cosmetic Preparations— Mouth Washes and 
Tooth Pastes — Hair Dyes, Hair Restorers and Depilatories — Cosmetic Adjuncts and 
Specialities— Colouring Cosmetic Preparations— Antiseptic Washes and Soaps— Toilet and 
Hygienic Soaps — Secret Preparations for Skin, Complexion, Teeth, Mouth, etc.— Testing and 
Examining the Materials Employed in the Manufacture of Cosmetics — Index. 

Glue, Bone Products and 
Manures. 

GLUE AND GLUE TESTING. By Samuel Rideal, D.Sc. 
|(Lond.), F.I.C. Fourteen Engravings. 144 pp. Demy 8vo. Price 
10s. 6d. net. (Post free, lOs. lOd. home ; lis. abroad.) 
Contents. 

Constitution and Properties: Definitions and Sources, Gelatine, Chondrin and Allied 
Bodies, Physical and Chemical Properties, Classification, Grades and Commercial Varieties 
-Raw Materials and Manufacture : Glue Stock, Lining, Extraction, Washing and Clari- 
fying, Filter Presses, Water Supply, Use of Alkalies, Action of Bacteria and of Anti8eptic8^ 
Various Processes, Cleansing, Forming, Drying, Crushing, etc., Secondary Products— Uses 
of Qlue : Selection and Preparation for Use, Carpentry, Veneering, Paper-Making, Book- 
binding, Printing Rollers, Hectographs, Match Manufacture, Sandpaper, etc.. Substitutes for 
other Materials, Artificial Leather and Caoutchouc— Gelatine : General Characters, Liquid 
Gelatine, Photographic Uses, Size, Tanno-, Chrome and Formo-Gelatine, Artificial Silk,. 
Cements, Pneumatic Tyres, Culinaiy, Meat Extracts, Isinglass, Medicinal and other Uses, 
Bacteriok^— Qlue Testing' : Review of Processes, Chemical Examination, Adulteration^ 
Physical Tests, Valuation of Raw Materials— Commercial Aspects. 



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9 

BONE PRODUCTS AND MANURES : An Account of the 
most recent Improvements in the Manufacture of Pat, Glue, Animal 
Charcoal, Size, Gelatine and Manures. By Ihomas Lambert, Techni- 
cal and Consulting Chemist. Illustrated by Twenty-one Plans and 
Diagrams. 162 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd. 
home ; 8s. abroad.) 

Contents. 

Chemical Composition of Bones — ^Arrangement of Factory — Properties of Glue — Olutin 
and Chondrin— Skin Glue— Liming of Skins— Wsishing— Boiling of Skin»— Clarification of Glue 
Liquors — Glue-Boiling and Clarifying-House— Specification or a Glue — Size — Uses and Pre- 
paration and Composition of Size—Concentrated Size — Properties of Gelatine — Preparation of 
Skin Gelatine — Drying — Bone Gelatine— Selecting Bones—Crashing— Dissolving — Bleaching 
— Ek>iling — Properties of Glutin and Chondrin — ^Testing of Glues and Gelatines — The Uses m 
Glue, Gelatine and Size in Various Trades — Soluble and Liquid Glues— Steam and Waterproof 
Glues— Manures— Importation of Pood Stuffs— Soils— Germination— Plant Life— Natural 
Manures— Water and Nitrogen in Farmyard Manure— Full Analysis of Farmyard Manure 
—Action on Crops— Water<31oset System— Sewage Manure— Green Manures— Artificial 
Manures— Mineral Manures— Nitrogenous Matters— Shoddy— Hoofs and Horns— Leather 
Waste — ^Dried Meat — Dried Blood — Superphosphates — Composition— Manufacture — Common 
Raw Bones — Degreased Bones — Crude Fat — Refined Fat — Degelatinised Bones— Animal 
Charcoal— Bone Superphosphates — Guanos — Dried Animal Products — Potash Compounds- 
Sulphate of Ammonia— Extraction in Zacuo— French and British Gelatines compared— Index. 

Chemicals, Waste Products and 
Agricultural Cliemistry. 

REISSUE OP CHEMICAL ESSAYS OF C. W. 
SCHEELE. First Published in English in 1786. Trans- 
lated from the Academy of Sciences at Stockholm, with Additions. 900 
pp. Demy 8vo. Price 5s. net. (Post free. 5s. 6d. home ; 5s. 9d. abroad.) 
Contents. 

Memoir : C. W. Scheele and his work (written for this edition by J. G. Mcintosh)— On 
Fluor Mineral and its Acid — On Fluor Mineral — Chemical Investigation of Fluor Acid, 
with a View to the Earth which it Yields, by Mr. Wiegler— Additional Information 
Concerning Fluor Minerals— On Manganese, Magnesium, or Magnesia Vitrariorum — On 
Arsenic and its Acid — Remarks upon Salts of Benzoin — On Silex, Clay and Alum — Analysis 
of the Calculus Vesical — Method of Preparing Mercurius Dulcis Via Humida — Cheaper and 
more Convenient Method of Preparing Pulvis Algarothi — Experiments upon Molybdaena 
— Experiments on Plumbago — Method of Preparing a New Green Colour — Of the De- 
composition of Neutral Salts by Unslaked Lime and Iron— On the Quantity of Pure Air which 
is Daily Present in our Atmosphere— On Milk and its Acid — On the Acid of Saccharum Lactis 
-<-On the Constituent Parts of Lapis Ponderosus or Tungsten— Experiments and Observations 
on Ether— Index. 

THE MANUFACTURE OF ALUM AND THE SUL- 
PHATES AND OTHER SALTS OF ALUMINA AND 
IRON. Their Uses and Applications as Mordants in Dyeing 
and Calico Printing, and their other Applications in the Arts Manufac- 
tures, Sanitary Engineering, Agriculture and Horticulture. Translated 
from the French of Lucien Geschwind. 195 Illustrations. 400 pp. 
Royal 8vo. Price 12s. 6d. net. (Post free, 13s. home ; 13s. 6d; abroad.) 

AMMONIA AND ITS COMPOUNDS : Their Manufacture 
and Uses. By Camille Vincent, Professor at the Central School of 
Arts and Manufactures, Paris. Translated from the French by M. J. 
Salter. Royal 8vo. 114 pp. Thirty-two Illustrations. Price 5s. net. 
(Post free, 5s. 4d. home ; 5s. 6d. abroad.) 
Contents. 

General Considerations : Various Sources of Ammoniacal Products ; Human Urine 
as a Source of Ammonia— Extraction of Ammoniacal Products from Sewasre— 
Extraction of Ammonia from Qas Liquor— Manufacture of Ammoniacal Com- 
pounds from Bones, Nitrogenous Waste* Beetroot Wash and Peat— Manufacture of 
Caustic Ammonia, and Ammonium Chloride, Phosphate and Carbonate— Recovery 
of Ammonia from the Ammonia-Soda Mother Liquors— index. 



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10 

INDUSTRIAL ALCOHOL. A Practical Manual on the 
Production and Use of Alcohol for Industrial Purposes and for Use as 
a Heating Agent, as an Illuminant and as a Source of Motive Power. 
By J. G. M*Int08h, Lecturer on Manufacture and Applications of 
Industrial Alcohol at The Polytechnic, Regent Street, London. 
Demy 8vo. 1907. 250 pp. With 75 Illustrations and 25 Tables. 
Price 7s. 6d. net. (Post free, 7s. 9d. home ; 8s. abroad.) 
Contents. 

Alcohol and Its Properties.— Bthylic Alcohol— Absolute Alcohol— Adulterations — 
Proi)ertie8 of Alcohol — Fractional Distillation — Destructive Distillation — Products c^ Com- 
bustion— Alcoholometfy-Proof Spirit— Analysis of Alcohol— Table showini; Correspondence 
between the Specific Gravity and Per Cents, of Alcohol over and under Proof— Other 
Alcohol Tables. Continuous Aseptic and Antiseptic Permentatloii and Sterlllsatioii 
In Industrial Alcohol Manufacture. The Manufacture of industrial Alcohol from 
Beets. — Beet Slicing Machines — Extraction of Beet Juice by Maceration, by Diffusion — 
PermentAtion in Beet Distilleries — Plans of Modem Beet Distillery. The Atanufactnre of 
Industrial Alcohol from Grain.— Plan of Modern Grain Distillery. The Manufacture of 
Industrial Alcohol from Potatoes. The Manufacture of Industrial Alcohol from 
Surplus Stocks of Wine, Spoilt Wine, Wine Marcs, and from Pruit in General. The Manu- 
facture of Alcohol from the Sugar Cane and Sugar Cane Molasses— Plans. Plant, etc., 
for the Distillation and Rectification of Industrial Alcohol.— The Caffey and other 
"Patent" Stills— Intermittent versus Continuous Rectification — Continuous Distillation — 
Rectification of Spent Wash. The Manufacture and Uses of Various Alcohol 
Derivatives, Ether, Haloid Ethers, Compound Ethers, Chloroform— Methyl and Amyl 
Alcohols and their Ethereal Salts, Acetone— Barbet's Ether, Methyl Alcohol and Acetone 
Rectifying Stills. The Uses of Alcohol In Manufactures, etc.— List of Industries in 
which Alcohol is used, with Key to Function of Alcohol in each Industry. The Uses off 
Alcohol for lighUnz, Heating, and Motive Power. 

ANALYSIS OF RESINS AND BALSAMS. Translated 
from the German of Dr. Karl Dietbrich. Demy 8vo. 340 pp. 
Price 7s. 6d. net. (Post free, 78. lOd. home ; 8s. 3d. abroad.) 

MANUAL OP AGRICULTURAL CHEMISTRY. By 

Herbert Ingle, P.I.C, Late Lecturer on Agricultural Chemistry, the 
Leeds University; Lecturer in the Victoria University. Second 
Edition, with additional matter relating to Tropical Agriculture, etc. 
438 pp. 11 Illustrations. Demy 8vo. Price 7s. 6d. net. (Post free, 
8s. home ; 8s. 6d. abroad.) 

Contents. 
Properties and Characteristics of the Elements.— Hydrogen— Oxygen— Heat of Com- 
bustion — Nitrogen — Carbon — Sulphur — Phosphorous — Potassium — Sodium — Fluorine — 
Magnesium — Iron — Chlorine — Aluminium — Silicon — Borax. The Atmosphere.'— Nitrc^en— 
Oxygen — ^Ar^on — Carbon Dioxide — Ammonia— Nitric Acid — Ozone — Solid Matter. The Soil* 
— Classification of Rocks— Quartz — Felspar — Mica — Clay — Sandstones — Shales — Limestones 
—Calcareous Rocks— Transported Soils. Formation of Soils.— By Water, Air, Earth 
Worms, Vegetation and Bacteria — Sand— Clay — Limestone — Humus— Classification of Soils. 
Reactions In Soils. — Diffusion — Gravitation— Nitrification — Soil Gases — ^Water of the Soil- 
Biology of the Soil— Electrolytic Dissociation Theory— Mass Action. Analysis of Soils.— 
Samphng — Mechanical and Chemical Analyses — Determination of Silica, Alumina, Ferric 
Oxide, Total Potash and Phosphoric Acid, Lime, Magnesia, Calcium Caiiwnate, Sulphuric 
Acid, Nitrates and Nitrites. Natural Manures.- Improvement of Soils— Farmyard Manure 
— Composition of Animal Excreta — Use of Litter, Straw, Peat, Bracken, Leaves, Sawdust, 
Tanners' Refuse— Fermentation and Preservation of Farmvard Manure. Other Omnic 
Manures.— Guano — Poultry and Fish Manures— Seaweed— Dried Blood— Bones— Meat 
Guano— Hair— Soot— Oil-cakes. Nitrogenous Manures.— Sodium Nitrate— Ammonium 
Sulphate— Phosphatic Manures— Tricalcum Phosphate— Coprolites— Phosphorites— Mineral 
Superphosphates— Basic Slag— Potash Manures— Composition of Principal Potash Salts- 
Various Manures— Common Salt — Gypsum— Limestone — Ferrous Sulphate — Gas Lime- 
Copper Sulphate. Anal^^sis of Manures. — Constituents— Determination of Nitrogen- 
Phosphoric Acid— Potassium — Valuation of Manures from Analysis. Constituent of 
Plants. — Carbohydrates— Sugar»— Starch— Dextrin— Glycogen— Inulin— Gums— Cellulose- 
Glucose— Fructose— Cane Sugar— Melctrose—Arabinose— Xylose— Lignose—Pectosc— Oly- 



oerol— Waxes— Organic Acids and their Salte. Bssentlal Oils and Resins.— Terpenes— 
Oxygenated Essential Oils— Essential Oils containing Sulphur— Resins. Nitrogenous Sab- 
stances^- Albuminoids— Amide»— Alkaloids— Chk>rophyll. The Plant. — Oerminatioo— 



Roots— Osmotic Pressure — Leaves^Assimilation— Flowers. Crops. — Cereals— Root Crops 
—Fodder Crops— Hay— Ventilating Stacks— Silage— Composition of Crops. The Animal.— 
Blood— Bones— Patty Tissue— Muscle— Digestion— Bile— Urine. Poods and Feeding.— 
Composition of Oil-cake— Bye-Products as Poods— Digestibility of Foods— Calorific Value of 
Poods— Feeding Standards— Manurial Value of Poods. Milk and Milk Products.— Pat- 
Albuminoids— Milk Sugars— Chemical Composition of Cow's Milk — Influence of Pood, Season 
and Milking Time — Milk Products— Cream— Skimmed Milk— Butter— Butter-milk— Cheese- 
Condensed Milk— Koumiss^ -Milk Preservation. Analysis of Milk and Milk Products.— 



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11 

Milk— Amount of Pat—Determination of Total Solids, Specific Gravity, Proteids, Milk Sugar 
— ^Adulteration of Milk — Detection of Preservatives^Butter — Butter Colouring-Cheese — 
Milk Standards. Various Products used in Asriculturc— Arsenioas Oxide— Bleaching 
Powder — Copper Salts — Disinfectants — Fungicides — Iron Sulphate — Mercuric Chloride- 
Plant Poisons. Appendix.— Atomic Weights— Hydrometer Scales— Metric System- 
Solubilities. Tropical Agriculture, etc.— Composition of Rain Wate^— Irrigation Water- 
Earth Worms— Motion of Water in Soil— Analysis of Soils— Green Manuring — Kraal Manure 
— Bats* Guano— Artificial Manures— The Plant— Rice— Maize— Millet— Cotton— Flax— Castor 
Seeds — Sunfiower— Composition of Various South African Grown Crops — ^Ash Constituents of 
Foods— Variations in the Composition of Milk— Butter— Fat— Bordeaux Mixture— Insecticides. 

THE UTILISATION OP WASTE PRODUCTS. A Treatise 
on the Rational Utilisation, Recovery and Treatment of Waste Pro- 
ducts of all kinds. By Dr. Thbodor Koller. Translated from the 
Second Revised German Bdiljon. Twenty-two Illustrations. Demy 
8vo. 280 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. 3d. 
abroad.) 

THE MANUFACTURE OF CHEMICAL MANURES. 

From the French of J. Fritsch. With 70 Illustrations and 4 Plates. 

[In preparation. 
The Contents will include Superphosphates, Guanos, Nitrate of Soda, Dried Blood Sulphate 
of Ammonia, Potashes, etc. 

Writing Inks and Sealing Waxes. 

INK MANUFACTURE : Including Writing, Copying, Litho- 
graphic, Marking, Stamping, and Laundry Inks. By Sigmund Lehner. 
Three Illustrations. Crown 8vo. 162 pp. Translated from the German 
of the Fifth Edition. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. 
abroad.) 

SEALING-WAXES, WAFERS AND OTHER ADHES- 
IVES FOR THE HOUSEHOLD, OFFICE, WORK- 
SHOP AND FACTORY. By H. C. Standage. Crown 
8vo. 96 pp. Price 5s. net. (Post free, 5s. dd. home ; 5s. 4d. abroad.) 
Contents. 



Materials Used for Maklnsr Sealing- Waxes— The Manufacture of Sealing-Waxes— 
Wafers-— Notes on the Nature of the Materials Used in Making Adhesive Compounds— Cements 
for Use in the Household— Office Gums, Pastes and Mucilages— Adhesive Compounds for 



Lead Ores and Compounds. 

LEAD AND ITS COMPOUNDS. By Thos. Lambert, 
Technical and Consulting Chemist. Demy 8vo. 226 pp. Forty Illus- 
trations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. 3d. abroad.) 

IContents. 

History — Ores of Lead — Geographical Distribution of the Lead Industry — Chemical and 
Physical Properties of Lead — Alloys of Lead — Compounds of Lead — Dressing of Lead Ores 
— Smelting ot Lead Ores — Smelting in the Scotch or American Ore-hearth — Smelting in the 
Shaft or Blast Furnace — Condensation of Lead Fume — Desilverisation, or the Separation 
of Silver from Argentiferous Lead — Cupellation— The Manufacture of Lead Pipes and 
Sheets — Protoxide of Lead — Litharge and Massicot — Red Lead or Minium — Lead Poisoning 
— Lead Substitutes — Zinc and its Compounds — Pumice Stone — Drying Oils and Siccatives 
—Oil of Turpentine Resin— Classification of Mineral Pigments— Analysis of Raw and Finished 
Products— Tables— Index. 

NOTES ON LEAD ORES : Their Distribution and Properties, 
By Jas. Fairie, F.G.S. Crown Svo. 64 pages. Price Is. net. 
(Post free, Is. 3d. home ; Is. 4d. abroad.) 

{White Lead and Zinc White Paints^ see p, 4.) 



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12 

Industrial Hygiene. 

THE RISES AND DANGERS TO HEALTH OF VARI- 
OnS OCCUPATIONS AND THEIR PREVENTION. 

By Leonard A. Parry, M.D., B.Sc. (Lond.)* 196 pp. Demy 8vo. 
Price 78. 6d. net. (Post free, 78. lOd. home ; 88. abroad.) 
Contents. 

Occupations which are Accompanied by the Generation and Scattering of Abnormal 
Quantities of Duat— Trades in which there is Danger of Metallic Poisoning— Certain Chemi- 
cal Trades — Some Miscellaneous Occupations — Trades in which Various Poisonous Vapours 
are Inhaled— Oeneral Hygienic Considerations — Index. 

Industrial Uses of. Air, Steam and 

Water. 

DRYING BY MEANS OF AIR AND STEAM. Bxplana- 
tion8, Pormulse, and Tables for Use in Practice. Translated from the 
German of B. Hausbrand. Two folding Diagrams and Thirteen Tables. 
Crown 8vo. 72 pp. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. 
abroad.) Contents. 

Bntish and Metric Systems Compared — Centigrade and Pahr. Thermometers— Estimation 
of the Maximum Weight of Saturated Aqueous Vapour which can be contained in 1 kilo, 
of Air at Different Pressure and Temperatures — Calculation of the Necessary Weight and 
Volume of Air, and of the Least Expenditure of Heat, per Drying Apparatus with Heated 
Air, at the Atmospheric Pressure : A , With the Assumption that the Air is Completely Satur- 
ated with Vapour both before Entry and after Exit from the Apparatus—^, When the 
Atmospheric Air is Completely Saturated before entiy^ but at its exit is only 3, ^ or } Saturated 
— C, When the Atmospheric Air is not Saturated with Moisture before Entering the Drying 
Apparatus — Drying Apparatus, in which, in the Drying Chamber, a Pressure is Artificially 
Created, Higher or Lower than that of the Atmosphere — Drying by Means of Superheated 
Steam, without Air— Heating Surface, Velocity of the Air Current, Dimensions of the Drying 
Room, Surface of the Drying Material, Losses of Heat — Index. 

(See also " Evaporating^ Condensing and Cooling ApparatuSj^* p. 26.) 

PURE AIR, OZONE AND WATER. A Practical Treatise 

of their Utilisation and Value in Oil, Grease, Soap, Paint, Glue and 

other Industries. By W. B. Cowell. Twelve Illustrations. Crown 

Svo. 85 pp. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. abroad.) 

Contents. 

Atmospheric Air; Lifting of Liquids ; Suction Process ; Prei>aring Blown Oils; Preparing 
Siccative Drying Oils — Compressed Air ; Whitewash — Liquid Air ; Retrocession — Purification 
of Water; Water Hardness — Pleshings and Bones — Ozonised Air in the Bleaching and De- 
odorising of Pats, Glues, etc. ; Bleaching Textile Pibres — Appendix : Air and Gases ; Pressure 
of Air at Various Temperatures ; Puel ; Table of Combustibles ; Saving of Puel by Hieating 
Peed Water; Table of Solubilities of Scale Making Minerals; British Thermal Units Tables ; 
Volume of the Plow of Steam into the Atmosphere ; Temperature of Steam — Index. 

THE INDUSTRIAL USES OF WATER. COMPOSI- 
TION — EFFECTS— TROUBLES — REMEDIES— RE- 
SIDUARY WATERS— PURIFICATION— ANALYSIS. 

By H. DB la Coux. Royal Svo. Translated from the French and 
Revised by Arthur Morris. 864 pp. 135 Illustrations. Price 10s. 6d. 
net. (Post free, lis. home; lis. 6a. abroad.) 
Contents. 

Chemical Action of Water in Nature and in Industrial Use — Composition of Waters- 
Solubility of Certain Salts in Water Considered from the Industrial Point of View— EfiFects on 
the Boilmg of Water— Effects of Water in the Industries— Difficulties with Watei^-Peed 
Water for Boilers— Water in Dyeworks, Print Works, and Bleach Works— Water in the 
Textile Industries and in Conditioning— Water in Soap Works— Water in Laundries and 
Washhouses— Water in Tanning— Water in Preparing Tannin and Dyewood Extracts— Water 
in Papermaking— Water in Photography— Water in Su^r Refining— Water in Making Ices 
and Bieverages— Water in Cider Making— Water in Brewmg— Water in Distillin^Preliminary 
Treatment and Apparatus— Substances Used for Prelimmaiy Chemical Purification— Com- 
mercial Specialities and their Employment— Precipitation of Matters in Suspension in Water 
—Apparatus for the Preliminary Chemical Purification of Water— Industrial Pilters— Indus- 
trial Sterilisation of Water— Residuary Waters and their Purification— Soil Piltration— 
Purification by Chemical Processes— Analyses— Index. 

{See Books on Smoke Prevention^ Engineering and Metallurgy , p, 26, etc) 



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13 

X Rays- 

PRACTICAL X RAY WORK. By Frank T. Addyman, 
B.Sc. (Lond.), F.I.C., Member of the Roentgen Society of London ; 
Radiographer to St. George's Hosjpital ; Demonstrator of Physics and 
Chemistiy, and Teacher of Radiography in $t. George's Hospital 
Medical School. Demy 8vo. Twelve Plates from Photographs of X Ray 
Work. Fifty-two Illustrations. 200 pp. Price 10s. 6d. net. (Post free, 
10s. lOd. home; lis. Sd. abroad.) 

Contents. 

Historical— Work leading up to the Discovery of the X Rs^va— The Discovery— Appam* 
tus and its Manajfement— Electrical Terms^Sources of Electricity— Induction Coils- 
Electrostatic Machines— Tubes— Air Pumps— Tube Holders and Stereoscopic Apparatus— 
Fluorescent Screen»— Practical X Ray Worlc— Installations— Radioscopy— Radiography- 
X Rays in Dentistry— X Raj's in Chemistry— X Rays in War— Index. 

List Of Plates. 

Frontispiece — Congenital Dislocation of Hip-Joint.— I., Needle in Finger.- II.« Needle in 
Foot.— III., Revolver Bullet in Calf and Leg.— IV., A Method of Localisation.- V , Stellate 
Fracture of Patella showing shadow of "Strappifl^".— VI., Sarcoma.— VII., Six-weeks-old 
Injury to Elbow showing new Growth of Bone.— VI II., Old Fracture of Tibia suid Fibula 
badly set.— IX., Heart Shadow.— X.. Fractured Femur showins Grain of Splint.— XI.. Bar- 
rell's Method of Localisation. 

India-' Rubber and Gutta Percha. 

INDIA-RUBBER AND GUTTA PERCHA. Second 
English Edition, Revised and Enlarged. Based on the French work of 
T. Seeligmann, G. Lamy Torrilhon and H. Palconnet by John 
Geddbs McIntosh. Royal 8vo. 100 Illustrations. 400 pages. Price 
12s. 6d. net. (Post free, 13s. home ; 13s. 6d. abroad.) [yust published. 
Contents. 

India- Rubber. — Indiarubber, Latex— Definitions— Laticiferous Vessels— Botsuiical Ori^io 
—Habitats— Methods of obtaining the Latex— Methods of Preparing Raw or Crude India- 
rubber — Rubber Cultivation in Various Countries— Climatology— Sou— Rational Culture and 
Acclimatisation of the Different Species of Indiarubber Plants — Classification of the Com- 
mercial Species of Raw Rubber— Physical and Chemical Properties of the Latex and of 
Indiarubber— General Considerations— Mechanical Transformation of Natural Rubber into 
Washed or Normal Rubber (Purification)— Softening, Cutting, Washing, Diying, Storage — 
Mechanical Transformation of Normal Rubber into Masticated Rubber— Vulcanisation of 
Normal Rubber — Chemical and Physical Properties of Vulcanised Rubber — Hardened Rubber 
or Ebonite — Considerations on Mineralisation and Other Mixtures — Coloration and Dyeing — 
Analysis of Natural or Normal Rubber and Vulcanised Rubber— Rubber Substitutes- 
Imitation Rubber — Analysis of Indiarubber. 

Qutta Percha.— Definition of Gutta Percha— Botanical Origin— Habitat— Climatology- 
Soil— Rational Culture— Methods of Collection — Felling and Ringing versus Tapping— Extrae- 
tion of Gutta Percha from Leaves by Toluene, etc.— Classification of the Different Species of 
Commercial Gutta Percha— Physical and Chemical Properties of Gutta Percha— Mechanical 
Treatment of Gutta Percha— Methods of Analysing Gutta Percha— Gutta Perchr Substitutes. 

Leather Trades. 

PRACTICAL TREATISE ON THE LEATHER IN- 
DUSTRY. By A. M. Villon. Translated by Frank T. 
Addyman, B.Sc. (Lond.), F.I.C., F.C.S.; and Corrected bv an Emi- 
nent Member of the Trade. 500 pp., royal 8vo. 12S Illustrations. 
Price 21s. net. (Post free, 21 s. 6d. home ; 22s. 6d. abroad.) 
Contents. 

Preface— Translator's Preface— List of lUustratioos. 

Part In Materials used In Tannlng^Skins : Skin and its Structure; 'Skins used in 
Tanning; Various Skins and their Uses — ^Tsmnin and Tanning Substsuices: Tsmnin; Barks 
(Oak); Barks other than Oak; Tanning Woods ; Tannin-bearing Leaves; Excrescences; 
Tan-bearing Fruits; Tan-bearing Roots and Bulbs; Tanning Juices; Tanning Substances 
used in Various Countries; Tannin Extracts; Estimation of Tannin suid Tannin Principles^ 

Part n., TannlBfl^-The Installation of a Tannery: Tan Furnaces; Chimneys, Boilers, 
etc.; Steam Engines— Grinding and Trituration of Tsmning Substances: Cutting up Bark; 
Grinding Bark; The Grinding of Tan Woods; Powdering Fruit, Galls and Grains; Notes on 
the Grinding of Bark— Msuiufacture of Sole Leather: Soaking; Sweating and Unhairing; 
Plumping and Colouring; Handling; Tanning; Tsmning Elephants* Hides; Drying; 
Striking or Pinning — Msuiufacture or Dressing Leather : Soaking ; Depilation ; New Pro- 
» for the Depilation of Skins; Tanning; Cow Hides; Horse Hides; Goat Skins; Manu- 



facture of Split Hides— On Various Methods of Tanning : Mechanical Methods ; Physical 
Methods; Chemical Methods; Tanning with Extracts— Quantity and Quality; Quantity; 
Net Cost; Quality of Leather— Various Manipulations of Tanned Leather: Second Tanning ; 
Grease Stains; Bleaching leather; Waterproofing Leather; Weighting Tanned Leather; 
Preservation of Leather— Tanning Various Skins. ^ j 

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Part III^ Cunying — Waxed Calf: Preparation; Shaving; Stretching or Slicking: 
Oiling the Grain ; Oiiif^ the Flesh Side; Whitening and Graining; Waxing; Finishing; Dry 
Finishing; Finishing in Colour; Cost— White Calf: Finishing in White— Cow Hide for 
Upper Leathers: Black Cow Hide; White Cow Hide; Coloured Cow Hide— Smooth Cow 
Hide— Black Leather— Miscellaneous Hides: Horse; Goat; Waxed Goat Skin; Matt Goat 
Skin— Russia Leather: Russia Leather; Artificial Russia Leather. 

Part IV., Bnamelled, Hunffvy and Chamoy Leather, Morocco, Parchment, Purs 
and Artificial Leather — Enamelled Leather: varnish Manufacture; Application of the 
Enamel; Enamelling in Colour— Hungary Leather: Preliminanr; Wet Work or Prepara- 
tion; Aluming; Dressing or Loft Work; Tallowinf{; Hungary Leather from Various Hides 
—Tawing : Preparatory Operations ; Dressing ; C^reing Tawed Skins ; Rugs — Chamoy Leather 
— Morocco: Preliminary Operations, Morocco Tanning; Mordants used in Morocco Manu- 
facture; Natural Colours used in Morocco Dyeing; Artificial Colours; Different Methods 
of Dveing; Dyeing with Natural Colours; Dyeing with Aniline Colours; Dyeing with 
Metallic Salts; Leather Printing ; Finishing Morocco ; Shagreen ; Bronzed Leather— Gilding 
and Silvering: Gilding; Silvering; Nickel and Cobalt — Parchment — Purs and Furriery: 
Preliminary Remarks ; Indigenous Furs ; Foreign Purs from Hot Countries ; Foreign Furs 
from Cold Countries ; Furs from Birds* Skins ; Preparation of Furs ; Dressing ; Colouring ; 
Preparation of Birds' Skins; Preservation of Furs— Artificial Leather: Leather mtode from 
Scraps; Compressed Leather; American Cloth; Papier M&ch6; Linoleum; Artificial Leather. 

Part v.. Leather Testlngr and the Theory of Tannlngr— Testing and Analysis of Leather ; 
Physical Testing of Tanned Leather; Chemical Analysis— The Theory of Tanning and the 
other Operations of the Leather and Skin Industry: Theory of Soaking; Theory of Un- 
hairing; Theory of Swelling; Theory of Handling; Theory of Tanning; Theory of the 
Action of Tannin on the Skin; Theory of Hunganr Leather Making; Theory of Tawing; 
Theory of Chamoy Leather Making ; Theory of Mineral Tanning. 

Part VI., Uses of Leather— Machine Belts: Manufacture of Belting; Leather Chain 
Belts ; Various Belts ; Use of Belts— Boot and Shoe-making : Boots and Shoes ; Laces — 
Saddlery : Composition of a Saddle ; Construction of a Saddle — Harness : The Pack Saddle- 
Harness — Military Equipment — Glove Making — Carriage Building — Mechanical Uses. 

Appendix, The World's Commerce fii Leather— Europe ; America ; Asia ; Africa : 
Australasia — I ndex. 

THE LEATHER WORKER'S MANUAL. Being a. Com- 
pendium of Practical Recipes and Working Pormulse for Curriers, 
Bootmakers, Leather Dressers, Blacking Manufacturers, Saddlers, 
Fancy Leather Workers. By H. C. Standage. Demy 8vo. 165 pp. 
Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. abroad.) 
Contents. 

Blackings, Polishes, Glosses, Dressings, Renovators, etc., for Boot and Shoe Leather — 
Harness Blackings, Dressings, Greases, Compositions, Soaps, and Boot-top Powders and 
Liquids, etc., etc. — Leather Grinders' Sundries — Currier's Seasonings, Blacking Compounds, 
Dressings, Finishes, Glosses, etc. — Dyes and Stains for Leather- Miscellaneous Information 
— Chrome Tannage — Index. 

{See '* Wood Products, Dtstillates and Extracts,^' p. 29). 

Books on Pottery, Bricks, 
Tiles, Glass, etc. 

MODERN BRICKMAKING. By Alfred B. Searle. Royal 
8vo. 440 pages. 260 Illustrations Price 12s. 6d. net. (Post free, 
138. home; 13s. 6d. abroad) [Just published. 

Contents. 
Nature and Selection of Clays.— Lake and River Deposited Clays— Rock Clays— Shale 
— Fire-clav. The Colour of Bricks.— Marls— White, Yellow, and Red Bricks— Terra -cotta— 
Blue Bricks. Qeneral Characteristics of Bricks.— Fletton, Bath, and Accrington Bricks 
— London Stocks — Plastic Bricks— Sand-faced Bricks — Glazed Bricks— Fire Bricks — Qualities 
of Bricks. Sand, Breeze, and other iVlaterlai8.—Chalk>water— General Manufacture of 
Bricks — Clav-washing— Haulage— Hand-Brickmaking-Preparation of the Paste— Pugging 
— Slop-moulding — Sand-moulding — Drying — Shrinking — Pressing — Clamp Kilns — Firing a 
Clamp. Plastic Moulding by Machinery.— Wire-cut Bricks— Brick Machines and Plant- 
Crushing Rolls— Grinding Mills— Wet Pans. Mixers and Feeders.- Pug-mills, Mouthpiece 
Presses, and Auger Machines — Expression Roller Machines— Cutting Tables — Repressing — 
Screw Presses— Eccentric Represses— Die-Boxes. Drying:.- Transport. Stiff -plastic 
Process. — Mill Feeding Machines — Grinding Mills-^EIevating — Screens — Sieves — Revolving 
Screens — Stiff-plastic Brickmaking Machines — Repressing — Carrying-off — Drying — Kilns. 
Semi- Dry or Semi-Plastic Process. — Lamination — Drying Troubles — Moulds and Arrises. 
The Dry or Dust Process.— Lamination. Kilns.- Down-draught Kiln&— Horizontal-draught 
Kilns — Continuous Kilns — Up-draught Kilns — Newcastle Kiln — Gas-fired Kilns — Semi-con- 
tinuous Kilns — Hoffmann Kilns — Hot-air Flues — ^Temporary and Permanent Flues — Chamber 
Kilns — Steam — Draught — Mechanical Draught — Gas-fired Continuous Kilns — Muffle Kilns — 
Kiln Construction. — Choice of Bricks — Foundations — Construction of Arches and Crowns — 
Fire Boxes— Peed-holes Chimneys— Selecting a Kiln. Setting and Burning:. — Up-draught 
and Down-draught Kilns — Horizontal-draught or Continuous Kiln — Glazed Bricks. Firing'. — 



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15 

Drying or Steaming—Volatilization— Pull Fire — Smoking — Seger Cones— Draaght Gauge- 
Cooling. Vitrified Bricks for Special Work.— Clinkers and Paving Bricks— Acid-proof 
Bricks. Plre-Brlcks and Blocks.— Materials— Orog— Grinding— Bkxsks— Drying— Dipped 
Fire-bricks — Firing — Silica Bricks — Ganister Bricks— Bauxite and Magnesia Bricks — 
Neutral Fire-bricks. Qlazed Bricks.— Pressing— Dipping— Glazes— Coloured Glazes— Ma- 
jolica Glazes— Piring—Salt-glazed Bricks. Perforated, Radial, and Hollow Bricks.— 
Fireproof Flooring. Moulded and Ornamental Bricks— Drying Raw Clay— Sources of 
Difficulty and Loss.- Improper Materials or Site— Unsuitable Methods of Working — Lack 
of Capital— Defective Accountmg. — Index. 

THE MANUAL OF PRACTICAL POTTING. Compiled 
by Experts, and Edited by Chas. P. Binns. Third Edition, Revised 
and Enlarged. 200 pp. Demy 8vo. Price 178. 6d. net. (Post free 
17s. lOd. home; 18s. Sd. abroad.) 

POTTERY DECORATING. A Description of all the Pro- 
cesses for Decorating Pottery and Porcelain. By R. Hainbach. 
Translated from the German. Crown Svo. 250 pp. Twenty-two 
Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.) 

Contents. 

Qlazes and Bngobes. — Glazes and Their Composition-^Glaze Materials — ^The Prepara- 
tion of Glazes— Coloured Glazes— Engobes and Glazes for same — Porcelain Glazes. Ceramic 
Colours.- Preparation of Pure Colours — Underglaze Colours — Applying the Colours on 
Earthenware — Glost Fire Colours — Mu£Ele Colours— Decorating Porcelain with Metals — 
Decorating Porcelain by Electroplating — Lustre Decorating on Porcelain — Firing Muffle 
Colours— Imitation of Paintings on Porcelain — Index. 

ARCHITECTURAL POTTERY. Bricks, Tiles, Pipes, Ena- 
melled Terra-cottas, Ordinary and Incrusted Quarries, Stoneware 
Mosaics, Faiences and Architectural Stoneware. By Leon LbfIivrb. 
Translated from the French by K. H. Bird, M.A., and W. Moore 
Binns. With Five Plates. 950 Illustrations in the Text, and numerous 
estimates. 500 pp., royal Svo. Price 15s. net. (Post free, 15s. 6d. 
home; 16s. 6d. abroad.) 

Contents. 
Part I., Plain Undecorated Pottery.— Chapter I., Clays : Sec. 1, Classification, General 
Geological Remarks— Classification, origin, locality ; Sec. 2, General Properties and Composi- 
tion : physical properties, contraction, analysis, influence of various substances on the 
properties of clays; Sec. 3, Working of Clay Pits — I. Open pits — II. Underj^round pits — 
Mining Laws. Chapter II., Preparation of the Clay : Crushing cylinders and mills, pounding 
machines — Damping: damping machines— Soaking, Shortening, Pugging: horse and steam 
pug-mills, rolling cylinders — Particulars of the above machines. Chapter III., Bricks : Sec. 1, 
Manufacture^!) Hand and machine moulding. — I. Machines working by compression : on soft 
clay, on semi-firm clay, on firm clay, on dry clay. — II. Expression machines— Dien — Cutting- 
tables — Particulars of the above machines — Types of installations — Estimates — Planishing, 
hand and steam presses, particulars — (2) Drying — Di^ing-roams in tiers, closed drying-rooms, 
in tunnels, in galleries — I>etailed estimates of the various drying-rooms, comparison of prices — 
Transport from the machines to the drying-rooms — (3) Firing — ^1. In clamps — II. In intermittent 
kilns. A. Open : a. using wood ; b. coal ; b'. in clamps ; 6". flame — B. Closed : c. direct flame ; 
c'. rectangular ; c". round ; d. reverberatory— III. Continuous kilns. C. With solid fuel : round 
kiln, rectangular kiln, chimneys (plans and estimates) — D. With gas fuel, Pillard kiln (plans and 
estimates), Schneider kiln (plans and estimates), wat«r-fias kiln — Heat production of the kilns ; 
Sec. 2, Dimensions, Shapes, Colours, Decoration and Quality of Bricks — Hollow bricks- 
Dimensions and prices of bricks, various shapes, qualities — ^Various hollow bricks, dimensions, 
resistance qualities ; Sec. 3, Applications — History — Asia, Africa, America, Europe : Greek, 
Roman, Byzantine, Turkish, Romanesque, Gothic, Renaissance. Chapter IV., Tiles: Sec. I, 
History; etc. 

Part 11., Made-up or Decorated Potter^.— Chapter I., General Remarks on the 
Decoration of Pottery: Dips — Glazes: composition, colouring, preparation, harmony with 
pastes — Special processes or decoration — Enamels, opaque, transparent, colours, under-glaze, 
over-glaze-^ther processes. Chapter II., Glazed and Enamelled Bricks— History: Glazing 
—Enamelling— Applications— Enamelled tiles. Chapter III., Decorated Quarries: I. Paving 
Quarries— 1. Decorated with dips— 2. Stoneware: A. Fired to stoneware; a. of slag baae-^ 
Applications ; b. of melting clay — ^Applications — B. Plain or incrusted stoneware ; a. of special 
clay (Stoke-on-Trent)-^Manufacture — Application — 6. Of felspar base — Colouring, manu- 
facture, moulding, drying, firing — Applications. II. Factng Quarries — 1. In htYence — A. Of 
timestone paste— fj. Of silicious paste — C. Of felspar paste — Manufacture, firing— 2. Of glazed 
Btonewar^— 3. Of porcelain — ^Applications of facing quarries. III. Stove Quarries — Prepara- 
tion of the pastes, moulding, firing, enamelling, decoration — Applications. Chapter IV., 
Architectural Decorated Pottery: Sec. 1, Faiences; Sec. 2, Stoneware; Sec. 3, Porcelain. 
Chapter V., Sanitary Pottery : Stoneware Pipes — Manufacture, firing— Applications— Sinks- 
Applications — Urinals, seats and pans — Applications— Drinking fountains, wash-stands. Index . 



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16 

CERAMIC TSCHNOLOOY : Being some Aspects of Tech- 
nical Science as Applied to Pottery Manufacture. Edited by Charles 
P. BiNNS. 100 pp. Demy 8vo. Price 12s. 6d. net. (Post free, 
12s. lOd. home; 13s. abroad.) 

Contents. 

Preface— The Chemistry of Pottery — Analysis and Synthesis — Clay« and their Com- 
ponents — The Biscuit Oven — Pyrometry — Glazes and their Composition — Colours and 
Colour-making — I ndex. 

THE ART OF RIVETING GLASS, CHINA AND 
EARTHENWARE. By J. Howarth. Second Edition. 
Paper Cover. Price ls.net. (By post, home or abroad, Is. Id.) 

NOTES ON POTTERY CLAYS. The Distribution, Pro- 
perties, Uses and Analyses of Ball Clays, China Clays and China 
Stone. ByjAS. Pairib, F.G.S. 182 pp. Crown 8vo. Price 3s. 6d. 
net. (Post free, 3s. 9d. home ; 3s. lOd. abroad.) 

A Reissue of 
THE HISTORY OF THE STAFFORDSHIRE POTTER. 
lES ; AND THE RISE AND PROGRESS OF THE 
MANUFACTURE OF POTTERY AND PORCELAIN. 

With References to Genuine Specimens, and Notices of Eminent Pot- 
ters. By Simeon Shaw. (Originally published in 1829.) 265 pp. 
Demy 8vo. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 9d. abroad.) . 

A Reissue of 
THE CHEMISTRY OF THE SEVERAL NATURAL 
AND ARTIFICIAL HETEROGENEOUS COM- 
POUNDS USED IN MANUFACTURING POR- 
CELAIN, GLASS AND POTTERY. By Simeon Shaw. 
(Originally published in 1837.) 750 pp. Royal 8vo. Price lOs. net. 
(Post free, 10s. 6d. home ; 12s. abroad.) 

BRITISH POTTERY MARKS. By G. Woolliscroft Rhead. 
Demy 8vo. 310 pp. With Fourteen Illustrations in Half-tone and 
upwards of Twelve-hundred Marks in the Text. Price 7s. 6d. net. (Post 
free, 8s. home ; 8s. 3d. abroad.) [yusi published. 



Glassware, Glass Staining and 
Paintinge 

RECIPES FOR FLINT GLASS MAKING. By a British 
Glass Master and Mixer. Sixty Recipes. Being Leaves from the 
Mixing Book of several experts m the Flint Glass Trade, containing 
up-to-date recipes and valuable information as to Crystal, Demi -crystal 
and Coloured Glass in its many varieties. It contains the recipes for 
cheap metal suited to pressing, blowing, etc., as well as the most costly 
crystal and ruby. Second Edition. Crown 8vo. Price 10s. 6d. net. 
(Post free, 10s. 9d. home ; 10s. lOd. abroad.) 
Contents. 

Ruby— Ruby from Copper^ Flint for using with the Ruby for Coating — A German Metal — 
Cornelian, or Alabaster— Sapphire Blue — Crysophis — Opal — ^Turquoise Blue — Gold Colour- 
Dark Green— Green (com.-non)— Green for Malacnite— Blue for Malachite— Black for Mala* 
chite — Black— Common Canary Batch — Canary— White Opaque Glass — Sealing-wax Red — 
Flint- Flint Glass (Crystal and Demi)— Achromatic Glass— Paste Glass— White tfnamel— 
Firestone- Dead White (for moons) — White Agate — Canary— Canary Enamel- Index. 



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A TREATISE ON THE ART OF GLASS PAINTING. 

Prefaced with a Review of Ancient Glass. By Ernest R. Suppling. 
With One Coloured Plate and Thirty-seven Illustrations. Demy 8vo. 
140 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.) 
Contents. 

A Short History of Stained Glass— Designing Scale Drawings— Cartoons and the Cut Line 
— Various Kinds of Glass Cutting for Windows— The Colours and Brushes used in Glass 
Painting— Painting on Glass, Dispersed Patterns— Diapered Patterns— Adding— Firing— 
iPret Lead Glazing— Index. 

PAINTING ON GLASS AND PORCELAIN AND 
ENAMEL PAINTING. A Complete Introduction to the 
Preparation of all the Colours and Fluxes used for Painting on Porce- 
lain. Enamel. Faience and Stoneware, the Coloured Pastes and Col- 
oured Glasses, together with a Minute Description of the Firing of 
Colours and Enamels. By Felix Hermann, Technical Chemist. With 
Eighteen Illustrations. 300 pp. Translated from the German second 
and enlarged Edition. Price 10s. 6d. net. (Post free, 10s. lOd. home ; 
lis. abroad.) 

Paper Making, Paper Dyeing, 
and Testing. 

THE DYEING OP PAPER PULP. A Practical Tieatise for 
the use of Papermakers, Paperstainers. Students and others. By 
Julius Erfurt, Manager of a Paper Mill. Translated into English 
and Edited with Additions by Julius HObner, F.C.S., Lecturer on 
Papermaking at the Manchester Municipal Technical School. With 
Illustrations and 157 patterns Of paper dyed in the pulp. Royal 
8vo, 180 pp. Price 15s. net. (Post free. 15s. 6d. home; 16s. 6d. abroad.) 

Contents. 
Behaviour off the Paper Fibres during: the Proceu off Dyeing, Theory of the 
Mordant— Colour Ptxing: Mediums (Mordants)— Influence off the Quality off the Water 
Used-lnors«nic Colours— Orsanic Colours— Practical Application of the Coal Tar 
Colours according to their Properties and their Behaviour towards the Dlfffereot 
Paper Fibres— Oyed Patterns on Various Pulp Mixtures— Dyeing to Shade— Index. 

THE PAPER MILL CHEMIST. By Henry P. Stevens, 
M.A., Ph.D., F.I.C. Royal 12mo. 60 Illustrations. 300 pp. Price 
7s. 6d. net. (Post free 7s. 9d. home ; 7s. lOd. abroad.) 
Contents. 

Introduction. — Dealing with the Apparatus required in ChemicsU Work and General 
■Chemical Manipulation, introducing the subject of Qualitative and Quantitative Analysts. 
Fuels.— Analysis of Coal, Coke and other Fuels— Sampling and Testing for Moisture, Ash, 
Calorific Value, etc.— Comparative Heating Value of different Fuels and Relative Efficiency. 
Water.— Analysis for Steam Raising and for Paper Making Purposes generally— Water 
Softenmg and Purification — ^A List of the more important Water Softening Plant, giving 
Power required, Weight, Space Occupied, Out-put and Approximate Cost. Raw Materials 
and Detection of Adulterants.— Analysis and Valuation of the more important Chemicals 
■used in Paper Making, including Lime. Caustic Soda, Sodium Carbonate, Mineral Acids, 
Bleach Antichlor, Alum, Rosin and Rosin Size, Glue Gela in and Casein, Starch, China Clay, 
Blanc Fixe, Satin White and other Loading Materials, Mineral Colours and Aniline Dyes. 
Manufacturing Operations.— Rags and the Chemical Control of Rag Boiling— Esparto 
Boiling— Wood Boiling— Testing Spent Liquors and Recovered Ash— Experimental Tests 
with Raw Fibrous Materials— Boiling in Autoclaves— Bleaching and making up Hand Sheets 
— Examination of Sulphite Liauors— Estimation of Moisture in Pulp and Hair-stuff— Recom- 
mendations of the British Wood Pulp Association, i-inlshed Products.— Paper Testing, 
including Physical, Chemical and Microscopical Tests, Area, Weight, Thickness, Apparent 
Specific Gravity, Bulk or Air Space. Determination of Machine Direction, Thickness, 
Strength, Stretch, Resistance to Crumpling and Friction, Transparency, Absorbency and 
-other qualities of Blotting Papers — Determination of the Permeability of Filtering Papers — 
Detection and Estimation of Animal and Vegetable Size in Paper— Sizing Qualities of 
Paper— Fibrous Constituents — Microscopical Examination of Fibres— The Efrect of Beating 
on Fibres— Staining Fibres— Mmeral Matter— Ash — Qualitative and Quantitative Examina- 
tion of Mineral Matter— Examination of Coated Papers and Colouring Matters in Paper. 



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18 
Contents of *'Tlie Paper Mill Cfiemlst'*— continued. 

TablM. — English and Metrical Weights and Measures with Equivalents — Conversion of 
Orams to Grains and vice v^rsa— Equivalent Costs per lb., cwt.,and ton — Decimal Equivalents 
of lbs., qrs., and cwts.— Thermometric and Barometric Scales— Atomic Weights and Moleculau* - 
Weights — Factors for Calculating the Percentage of Substance Sought from the Weight of 
Substance Pound—Table of Solubilities of Substances Treated of in Paper Making— SpeciHc 
Gravity Tables of such substances as are used in Paper Making, including Sulphuric Acid, 
Hydrochloric Acid, Bleach, Milk of Lime, Caustic Soda, Carbonate of Soda, etc., giving 
Percentage Strength with Specific Gravity and Degrees Tw.— Hardness Table for Soap 
Tests— Dew Point— Wet and Dry Bulb Tables— Properties of Saturated Steam, giving 
Temperature, Pressure and Volume— List of Different Machines used in the Paper Making 
Industrv, giving Size, Weight. Space Occupied, Power to Drive, Out-put and Approximate - 
Cost— Calculation of Moisture in Pulp— Rag- Boiling Tables, giving Percentages of Lime, 
Soda and Time required— Loss in Weight in Rags and other Raw Materials during Boiling 
and Bleaching— Conditions of Buying and Selling as laid down by the Paper Makers* Associa- 
tion—Table of Names and Sizes of Papers— Table for ascertaining the Weight per Ream from 
the Weight per Sheet— Calculations of Areas and Volumes— Logarithms— Blank pages foe- - 
Notes. 

THE TREATMENT OF PAPER FOR SPECIAIt. 
PURPOSES. By L. E. And6s. Translated from the 
German. Crown 8vo. 48 Illustrations. 250 pp. Price 6s. net. (Post 
free, 6s. 4d. home ; 6-:. 6d. abroad.) 

Contents. 

1., Parchment Paper, Vegfetable Parchment.— The Parchment Paper Machine- 
Opaque Supple Parchment Paper — Thick Parchment — Kru^ler's Parchment Paper and Parch- 
ment Slates— Double and Triple Osmotic Parchment— Utilising Waste Parchment Paper— 
Parchmented Linen and Cotton — Parchment Millboard — Imitation Horn and Ivory from 
Parchment Paper— Imitation Parchment Paper— Artificial Parchment— Testing the Sulphuric 
Acid. II., Papers for Transfer Pictures. III., Papers for Preservative and Packing: 
Purposes. — Butter Paper — Wax Paper — Paraffin Paper — ^Wrapping Paper for Silverware — 
Waterproof Paper — Anticorrosive Paper. IV., Grain^l Transfer Papers. V., Fireproof and 
Antifalsification Papers. VI., Paper Articles.— Vulcanised Paper Machd— Paper Bottles- 
Plastic Articles of Paper — Waterproof Coverings for Walls and Ceilings — Paper Wheels,. 
Roofing and Boats — Pa er Barrels— Paper Boxes — Paper Horseshoes. Vll., Gummed Paper. 
VIII., Hectograph Papers. IX., Insecticide Papers.— Fly Papers-Moth Papers. X., 
Chalk and Leather Papers.- Glacd Chalk Paper— Leather Papei^-Imitation Leather.. 
XI., Luminous Papers— Blue- Print Papers— Blotting Papers. XII., Metal Papers— Medi- 
cated Papers. XIII., Marbled Papers. XIV., Tracing and Copying Papers — Iridiscent or 
Mother of Pearl Papers. XV., Photographic Papers— Shellac Paper— Fumigating Papers — 
Test Papers. XVI., Papers for Cleanln&r and Polishinflr Purposes— Glass Paper— 
Pumic Paper— Emery Paper. XVII., Lithographic Transfer Papers. XIX., Sundry 
Special Papers— Satin Paper— Enamel Paper— Cork Paper— Split Paper— Electric Paper- 
Paper Matches— Magic Pictures— Laundry Blue Papers— Blue Paper for Bleachers. XX., 
Waterproof Papers— Washable Drawing Papers— Washable Card— Washable Coloured Paper 
—Waterproof Millboard— Sugar Paper. XXI., The Characteristics of Paper— Paper Testing. 

Enamelling on Metal. 

ENAMELS AND ENAMELLING. For Enamel Makers, 
Workers in Gold and Silver, and Manufacturers of Objects of Art. 
By Paul Randau. Translated from the German. With Sixteen Illus- 
trations. Demy 8vo. 180 pp. Price 10s. 6d. net. (Post free, 10s. lOd. 
home; lis. abroad.) 

THE ART OF ENAMELLING ON METAL. By W. 

Norman Brown. Twenty-eight Illustrations. Crown Svo. 60 pp. 
Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.) 

Silk Manufacture. 

SILK THROWING AND WASTE SILK SPINNING. 

By HoLLiNS Rayner. Demy Svo. 170 pp. 117 Illus. Price Ss. net.. 
(Post free, 5s. 4d. home ; 5s. 6d. abroad.) 
Contents. 

The Silkworm— Cocoon Reeling and Qualities of Silk— Silk Throwing— Silk Wastes— The- 
Preparation of Silk Waste for Degumming— Silk Waste Degumming, Schapping and Dis- 
Charging— The Opening and Dressing of Wastes— Silk Waste "Drawing" or "Preparing"" 

f— Short Spinning— Spinning and "----*---'* ** »t^.i:— ..; — 
pinning— Exhaust Noil Spinning. 



Machinery— Long Spinning— Short Spinning— Spinning and Finishing Processes— Utilisation* 
of Waste Products— Noil Spinning— Exhaust Noil Spinnin 



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19 

Books on Textile and Dyeing 
Subjects. 

THE FINISHING OF TEXTILE FABRICS (Woollen, 
Worsted, Union and other Cloths). By Roberts Beaumont, M.Sc, 
M.I.Mech.E., Professor of Textile Industries, the University of Leeds; 
Author of " Colour in Woven Design " ; *' Woollen and Worsted Cloth 
Manufacture " ; " Woven Fabrics at the World's Fair " ; Vice-President 
of the Jury of Award at the Paris Exhibition, 1900; Inspector of Tex- 
tile Institutes ; Society of Arts Silver Medallist ; Honorary Medallist 
of the City and Guilds of London Institute. With 150 Illustrations of 
Fibres, Yarns and Fabrics, also Sectional and other Drawings of 
Finishing Machinery. Demy 8vo, 260 pp. Price 10s. 6d. net. (Post 
free, 10s. lOd. home; lis. 3d. abroad.) [yust Published. 

Contents. 
I., Woollen, Worsted and Union Fabrics.~Secttons (1) Woollen Cloths : Saxonies and 
Cheviots— (2) Worsted Fabrics: Botany and Crossbred— (3) Fancy and Piece-dye Woollens 
—(4) Fancy and Piece-djje Worsteds— (5) Union Fabrics: Piece-dyes and Fancies — (6) Whip- 
cords, Buckskins, Venetians, Cords and Twist warp Fancies — (7) Heavy Woollens: Box 
Cloths, Meltons, Pilots— (8) Friezes, Shetland^ and Naps— (9) Special Types of Overcoatings 
-(10) Golf Cloakinf^s— (11) Vestings. II., Processes off Pinlshlnfl: and their Effects.— 
Sections— (12) Qualities of Unfinished Woollens— (13) Worsted Fabrics and Finishing— (14) 
Preliminary Work— (15) Finishing Processes— (16) Scouring and the Detergents Used — (17) 
Hydro-extracting— (18) Tentering and Drying— (19) Felting and its Effects— (20) Condition of 
the Piece in Milling— (21) Potash and Soda Soaps— (22) Effects of Raising— (23) Influence of 
Textural Conditions on Raising— (24) Theory of Raising and the Twine in the Yarn— (25) Fabric 
Structure and Raising Surface— (26) Several Kinds of Raising— (27) Lustring Proceses— (28) 
Pressing. III., The Process of Scouring: : Scouring: Machines.- Sections (29) Impurities in 
Greasy Pieces— (30) Scouring Machines— (31) The Rope Machine : Scouring Operation— (32) 
Washing-off— <33) Points in the Use of the Rope Scourer- (34) The Open Scourer: Construc- 
tion— (35) Advantages of the Open Scourer— (36) Scouring Machine with Flanged Rollers- (87) 
Combined Scouring and Milling Machine. IV., Theory off Felting:.— Sections (38) Qualities 
of Wool in Relation to Felting— <39) Shrinkage Properties of Merino and Cheviot Wools— (40) 
Felting Contrasts, Merino and Southdown Wools— (41) Utility in Woven Manufactures of 
Wools of Different Shrinking Qualities— (42) Yarn Structure— (43) Felting Affected by Yam 
Composition — (44) Methods of Yarn Construction and Felting— (45) Shrinkage of Fabrics made 
of Re-manufactured Fibres— (46) D<^gree of Twine in the Yam— (47) Folded Yarns and Shrink- 
age, v.. Theory of Felting: Fabric Structure.— Sections (48) Build of the Fabric— (49) 
Felting Quality or Standard weaves— (50) Influence of Intersections— (51) Variation in Wefting 
—(52) Irregular Weaves and Felting— (53) Felting of Two-ply Warp and Weft Fabrics— (54) 
Relative Shrinkage of Single and Backed Weaves. VI., Theory off Pelting: : Compound 
Fabrics.— Sections (55)— Structure of Backed Fabrics and the Felting Quality of the Cloth— 
(56) Three-ply Weft Fabrics— (57) Yarn Characteristics in Compound Weft Fabrics— (58) 
Fabrics Compound in the Warp — (59) Felting of Compound Weaves— (60) Double Cloths and 
Varied Felting— (61) Stitching or Tying of Double and Compound Weaves and the Effects on 
Milling. VII., Pullinfl: and Milling: Machinery.— Sections (62) "Fulling" and ''Milling" 
—(63) Routine in the Fulling Stocks and Milling Machine— (64) Construction and Working of 
the Fuller Siocks— (65) Milling Machines— (66) Routine of Milling— (67) Corrugated Guide 
Rollers— (68) Machines with Tvsro or More Upper Rollers— (69) Dupl x Machines— (70) Machines 
without Flanged Rollei^-(71) Mechanical Devices applied to the Spout— (72) Roller Milling 
Machine with Stampers in the Spout — (73) Principle of Combined Milling Machine and Stocks 
--(74) Combined Scouring and Milling— (75) Milling without Artificial Compression. VIII., 
The Theory off Raising:.- Sections (76) Treatment of the Cloth— (77) Condition of the Cloth 
—(78) Dry Raisinc— (79) Damp and Wet Raising— (80) Raising Determined by the Degree of 
Felting— (81) Quality of the Material and the Raised Result— (82) Raising and Weave Structure 
—(83) Quality of the Fibre and Yarn Structure— (84) Raising^ of Fabrics in which Special or 
Fancy Yarns are used. IX., Raising: Machinery and the Raising: Process.— Sections (86) 
Hand Raising— (86) Raising Gig— (87) Operation of the Raising Gig— (88) Two-cylinder 
Raising Gig— <89) Teazle Raising— (90) Teazles and Card-wire Compared— (91) Card-wire 
Raising Machines— (92) Modern Card Raising Machinps— (93) The Horizontal Machine— 
(94) Rotary Machines. X., Cutting:, Cropping or Shearing:.— Sections— (97) Cropping 
—(98) The Effects of Cutting-H(99) Cutting Machines— (100) The Cross-Cutting Machine— 
(101) The Continuous Cutting Machine— (102)" Setting of the Cutting Parts— (103) Form 
of the Bar or «' Bed " under the Cutters— (104) Machines with Two or More Cylinders— (105) 
Grinding. XL, Lustring: Processes and Machinery.— Sections (106) The Production of 
Lustre on Woollen and Worsted Fabrics — (107) Steaming and Cooling Machines— (108) 
Pressing— (109) The Vertical Press— (110) The Rotary Press— (111) Intermittent Pressing 
Machine. XIL, Methods of Finishing:.— Sections (1 12) Routines of Finishing— (1 13) Woollen 
Routines of Finishing— (114) Worsted Routines of Finishing— (1 15) Routines of Finishing for 
<Union Fabrics— Index. 



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THE CHEMICAL TECHNOLOGY OF TEXTIXJ^ 
FIBRES: Their Origin, Structure, Preparation, Washings 
Bleaching, Dyeing, Printing and Dressing. By Dr. Gboro von 
Gboroibvics. Translated from the German by Charles Salter. 
320 pp. Forty-seven Illustrations. Royal 8vo. Price lOs. 6d. net- 
(Post free, lis. home ; lis. Sd. abroad.) 

POWER-LOOM WEAVING AND YARN NUMBERINO, 
According to Various Systems, with Conversion Tables. Translated 
from the German of Anthon Grunbr. With Twenty-Six Diaflrain^ 
In Colours. 150 pp. Crown 8vo. Price 7s. 6d. net. (Post free, 
7s. 9d. home ; 8s. abroad.) 

TEXTILE RAW MATERIALS AND THEIR COIT- 
VERSION INTO YARNS. (The Study of the Raw 
Materials and the Technology of the Spinning Process.) By Julius. 
ZiPSBR. Translated from German by Charlbs Salter. 302 Illus- 
trations. 500 pp. Demy 8vo. Price 10s. 6d. net. (Post free, Us^ 
home; lis. 6d. abroad.) 

GRAMMAR OF TEXTILE DESIGN. By H. Nisbbt, 

Weaving and Designing Master, Bolton Municipal Technical Schools 

Demy 8vo. 280 pp. 490 Illustrations and Diagrams. Price 6s. net. 

(Post free, 6s. 4d. home ; 6s. 6d. abroad.) 

Contents. 

The Plain Weave and its Modifications. Twill and Kindred Weaves.— ClasaiB- 

cation of Twill Weaves. Diamond and Kindred Weaves. Bedford Cords. Backei>' 

Fabrics. Fustians. Terry Pile Fabrics. Gauze and Leno Fabrics. Tissue, Lappet, 

and Swivel Figuring ; also Ondul^ Effects, and Looped Fabrics. 

ART NEEDLEWORK AND DESIGN. POINT LACE. A 

Manual of Applied Art for Secondary Schools and Continuation Classes. 
By M. E. Wilkinson. Oblong quarto. With 22 Plates. Bound in 
Art Linen. Price 3s. 6d. net. (Post free, 3s. lOd. home : 4s. abroad.)* 
Contents. 

Sampler of Lace Stitches— Directions for working Point Lace, tracing Patterns, etc. — 
List of Materials and Implements required for working. Plates 1., Simple Lmes, Straight andf 
Slanting, and Designs formed from them. IL, Patterns formed from Lines in previous 
Lesson. IIL, Patterns formed from Lines in previous Lesson. IV., Simple Curves, and 
Designs formed from them. V., Simple Leaf form, and Designs formed from it. 'VI., Ele- 
mentary Geometrical forms, with Definitions. VII., Exercises on previous Lessons. VIIL, 
Pilling of a Square, Oblong and Circle with Lace Stitches. IX., Design for Tie End, based 
on simple Leaf form. X., Lace Butter Hies (Freehand). XI.. Twenty simple Designs evolved 
from Honitoo Braid Leaf. XII., Design for Lace Handkerchief, based on previous Lesson. 
XIIL, Design for Tea-cosy. XIV., Freehand Lace Collar. XV., Freehand Lace Cuff (to< 
match). Xvl., Application of Spray from Lesson XI. XVII., Adaptation of Curves within* 
a Square, for Lace Cushion Centre. XVIII., Conventional Sprav for comer of Tea-cloth. 
XIX., Geometrical form for Rosebowl D'Oyley, to be originally filled in. XX., Geometrical^ 
form for Flower-vase D'Oyley, to be originally filled in. Bach Lesson contains Instructions- 
for Working, and application of new Stitches from Sampler. 

HOME LACE-MAKING. A Handbook for Teachers and 
Pupils. By M. E. W. Milroy. Crown 8vo. 64 pp. With 3 Plates- 
and 9 Diagrams. Price Is. net. (Post free, Is. 9d. home; Is. 4d. 
abroad.) 

THE CHEMISTRY OF HAT MANUFACTURING. Lec> 
tures delivered before the Hat Manufacturers' Association. By Wat- 
son Smith, F.C.S., F.I.C. Revised and Edited by Albert Shonk. 
Crown 8vo. 132 pp. 16 Illustrations. Price 7s. 6d. net. (Post free^ 
7s. 9d. home ; 7s. lOd. abroad.) 

THE TECHNICAL TESTING OF YARNS AND TEX- 
TILE FABRICS. With Reference to Official Specifica- 
tions. Translated from the German of Dr. J. Hbrzpeld. Second 
Edition. Sixty-nine Illustrations. 200 pp. Demy 8vo. Price 10s. 6d.. 
net. (Post free, 10s. lOd. home ; lis. abroad.) 

DECORATIVE AND FANCY TEXTILE FABRIC& 
By R. T. Lord. For Manufacturers and Designers of Carpets, Damask^ 
Dress and all Textile Fabrics. 200 pp. Demy 8vo. 132 Designs and 
Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.> 



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THEORY AND PRACTICE OF DAMASK WEAVING. 

B^ H. KiNZBR and K. Walter. Royal 8vo. Eighteen Folding Plates. 
Six Illustrations. Translated from the German. 110 pp. Price 8s. 6d. 
net. (Post free, 9s. home ; 9s. 6d. abroad.) 
Contents. 
The Various Sorts of Damask Fabrics— Drill (Tickjng, Handloom-made)— Whole- 
Damask for Tablecloths— Damask with Ground- and Connecting-warp Threads— Pumittire 
Damask— Lampas or Hangings— Church Damasks— The Manufacture of Whole Damask. 



Jacquard with the so-called Damask Machine— The Special '. 
tion of Two Tyings. 

FAULTS IN THE MANUFACTURE OF WOOLLEN 
GOODS AND THEIR PREVENTION. By Nicolas 
Reiser. Translated from the Second German Edition. Crown 8vo. 
Sixty-three Illustrations. 170 pp. Price 5s. net. (Post free, Ss. 4d. 
home ; 5s. 6d. abroad.) 

Contents. 

Improperly Chosen Raw Material or Improper Miiftures — Wrong Treatment of the 
Material in Washing, Carbonisation, Drying, Dyeing and Spinning-— Improper Spacing of the 
Goods in the Loom— Wrong Placimj of Colours— Wrong Weight or Width of the Goods 
—Breaking of Warp and Weft Threads— Presence of Doubles, Singles, Thick, Loose, 
and too Hard Twisted Threads as well as Tangles, Thick Knots and the Like— Errors in 
Cross-weaving — Inequalities, ».«., Bands and Stripes — Dirty Borders — Defective Selvedges — 
Holes and Buttons— Rubbed Places— Creases— Spots— Loose and Bad Colours— Badly Dyed 
Selvedges— Hard Goods— Brittle Goods— Uneven Goods — Removal of Bands, Stripes,. 
Creases and Spots. 

SPINNING AND WEAVING CALCULATIONS, especially 
relating to Woollens. Prom the German of N. Reiser. Thirty-four 
Illustrations. Tables. 160 pp. Demy 8vo. 1904. Price 10s. 6d. net. 
(Post free, 10s. lOd. home ; lis. abroad.) 
Contents. 

Calculating the Raw Material— Proportion of Different Grades of Wool to Furnish a 
Mixture at a Given Price— Quantity to Produce a Given Length — Yarn Calculations — Yam* 
Number— Working Cal culat ions — Calculating the Reed Count— Cost of Weaving, etc. 

WATERPROOFING OF FABRICS. By Dr. S. Mibrzinskk 
Crown Svo. 104 pp. 29 Illus. Price 5s. net. (Post free, 5s. 3d. home ; 
5s. 4d. abroad.) ' 

Contents. 

Introduction — Preliminary Treatment of the Fabric — Waterproofing with Acetate of 
Alumina — Impregnation of the Fabric — Drying — Waterproofing with Paraffin — Waterproofing 
• ' * . - ... - . . - ... ^^.- 



with Ammonium Cuprate — Waterproofing with Metallic Oxides — Coloured Wai 
Fabrics— Waterproofing with Gelatine, Tannin, Caseinate of I " — — -* -**— »-- •'— 
facture of Tarpaulin — British Waterproofing Patents — Index. 



Fabrics — Waterproofing with Gelatine, Tannin, Caseinate of Lime and other Bodies — Manu- 
facture of Tarpaulin — British Waterproofing Patents — Index. 

HOW TO MAKE A WOOLLEN MILL PAY. By John: 
Mackie. Crown Svo. 76 pp. Price ds. 6d. net. (Post free, 3s. 9d. 
home ; 3s. lOd. abroad.) 

Contents. 

Blends, Piles, or Mixtures of Clean Scoured Wools— Dyed Wool Book— The Order Book. 
—Pattern Duplicate Books — Management and Oversight — Constant Inspection of Mill De> 
partments— Importance of Delivering Goods to Time, Shade, Strength, etc.— Plums. 

(For " Textile Soaps and Oils ** see p, 7.) 

Dyeing, Colour Printing, 
Matching and Dye-stuffs. 

THE COLOUR PRINTING OF CARPET YARNS. Manual 
for Colour Chemists and Textile Printers. By David Paterson, 
P.C.S. Seventeen Illustrations. 136 pp. Demy Svo. Price 7s. 6d. 
net. (Post free, 7s. lOd. home ; 8s. abroad.) 
Contents. 

Structure and Constitution of Wool Fibre — Yarn Scourin^Scouring Materials — Water for 
Scouring — Bleaching Carpet Yams — Colour Making for Yam Printing — Colour Printing 
Pastes— Colour Recipes for Yam Printing— Science of Colour Mixing— Matching of Colours 
— ^*'Hank'* Printing— Printinfl Tapestry Carpet Yams— Yam Printing— Steaming Printed 
Yams — Washing of Steamed Yams — ^Aniline Colours Suitable for Yam Printing — Glossary of 
Dyes and Dye^wares used in Wood Yam Printing— Appendix. 



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22 

THE SCIENCE OF COLOUR MIXING. A Manual in- 
tended for the use of Elvers, Calico Printers and Colour Chemists. By 
David Paterson, P.C.S. Forty-one Illustrations, Five Goleured Plates, 
and Four Plates showingr Eleven Dyed Speolmene of Fabrics. 1S2 

pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. 
abroad.) 

Contents. 

Colour a Sensation ; Colours of Illuminated Bodies ; Colours of Opaque and Transparent 
Bodies ; Surface Colour — Analysis of Light ; Spectrum ; Hom<^eneous Colours ; Ready 
Method of Obtaining a Spectrum — Examination of Solar Spectrum; The Spectroscope and 
Its Construction ; Colourists' Use of the Spectroscope — Colour by Absorption ; Solutions and 
Dyed Fabrics; Dichroic Coloured Fabrics in Gaslight — Colour Primaries of the Scientist 
versus the Dyer and Artist: Colour Mixing by Rotation and Lye Dyeing; Hue, Purity, 
Brightness; Tints; Shades, Scales, Tones, Bad and Sombre Colours — Colour Mixing; Pure 
and Impure Greens, Orange and Violets ; Large Variety of Shades from few Colours ; Con- 
sideration of the Practical Primaries : Red, Yellow and Blue — Secondary Colours ; Nomen- 
clature of Violet and Purple Group ; Tints and Shades of Violet ; Changes in Artificial Light 
—Tertiary Shades ; Broken Hues; Absorption Spectra of Tertiary Shade»— Appendix : Four 
Plates with Dyed Specimens Illustrating Text— Index. 

DYERS' MATERIALS : An Introduction to the Examination, 
Evaluation and Application of the most important Substances used in 
Dyeing, Printing, Bleaching and Finishing. By Paul Heerman, Ph.D. 
Translated from the German by A. C. Wright, M.A. (Oxon.), B.Sc. 
(Lond.). Twenty-four Illustrations. Crown 8vo. 150 pp. Price 5s. 
net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 

COLOUR MATCHING ON TEXTILES. A Manual in- 
tended for the use of Students of Colour Chemistry, Dyeing and 
Textile Printing. By David Paterson, F.C.S. Coloured Frontis- 
piece. Twenty-nine Illustrations and Fourteen Speolmens Of Dyed 
Fabrics. Demy 8vo. 132 pp. Price 7s. 6d. net. (Post free, 7s. lOd. 
home ; 8s. abroad.) 

COLOUR: A HANDBOOK OF THE THEORY OF 
COLOUR. By George H. Hurst, F.G.S. With Ten 
Coloured Plates and Seventy-two Illustrations. 160 pp. Demy 8vo. 
Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.) 
Contents. 
Colour and its Production— Cause of Colour In Coloured Bodies— Colour Pheno- 
mena and Theories— The Physiology of Ligrht— Contrast— Colour in Decoration and 
Desiflrn- Measurement of Colour. 

Reissue of 

THE ART OF DYEING WOOL, SILK AND COTTON. 

Translated from the French of M. Hbllot, M. Macquer and M. lb 
PiLEUR D'Apligny. First Published in English in 1789. Six Plates. 
Demy 8vo. 446 pp. Price 5s. net. (Post free, 5s. 6d. home; 6s. 

^^'''>^^) contents. 

Part I., The Art of Dyeing: Wool and Woollen Cloth, Stuffs, Yam, Worsted, etc. 
Part II., The Art of Dyeing: Silk. Part III., The Art of Dyeing: Cotton and Linen 
Thread, tog:ether with the Metliod of Stamping: Silks, Cottons, etc. 

THE CHEMISTRY OF DYE-STUFFS. By Dr. Georg Von 
Georgievics. Translated from the Second German Edition. 412 pp. 
Demy 8vo. Price 10s. 6d. net. (Post free, lis. home ; lis. 6d. abroad.) 

THE DYEING OF COTTON FABRICS. A Practical 
Handbook for the Dyer and Student. By Franklin Beech, Practical 
Coiourist and Chemist. 272 pp. Forty-four Illustrations of Bleaching 
and Dyeing Machinery. Demy 8vo. Price 7s. 6d. net. (Post free, 
7s. ICki. home ; 8s. abroad.) 

THE DYEING OF WOOLLEN FABRICS. By Franklin 
Beech, Practical Coiourist and Chemist. Thirty-three Illustrations. 
Demy 8vo. 228 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 
8s. abroad.) 



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23 

Bleaching and Bleaching 
Agents. 

A PRACTICAL TREATISE ON THE BLEACHING OF 
LINEN AND COTTON YARN AND FABRICS. By 

L. Tailpbr, Chemical and Mechanical Engineer. Translated from the 
French by John Geddes McIntosh. Demy 8vo. 303 pp. Twenty 
Illus. Price 12s. 6d. net. (Post free, 13s. home ; 13s. 6d. abroad.) 

MODERN BLEACHING AGENTS AND DETERGENTS. 

By Professor Max Bottler. Translated from the German. Crown 
8vo. 16 Illustrations. 160 pages. Price 5s. net. (Post free, 5s. 3d. 
home ; 5s. 6d. abroad.) iyi*st published^ 

Contents. 
Part I., Bleachine Agents. Old and New Bleachlngr Methods and Bleachlnflp 
Agents. — Bleaching Agents for Wool — Bleaching with Permanganate — Perborates — Acid 
Sodium Percarbonate — Bleaching Agents for Silk— Bleaching Powder and Alkali Hypoch- 
lorites — Bleaching Processes — Bleaching Linen — Bleaching with Ozone — Bleaching Straw 
and Leather — Discharging Colours — Bleaching Jute and other Vegetable Fibres— Bleaching 
Various Substances— Electrical Bleaching Processes. Sodium Peroxide. — Properties — 
Dissolving Sodium Peroxide — Preparing the Bleaching Liquor— Compressed Sodium Peroxide 
— Sodium Peroxide in Bleaching— Cleaning Materials to be Bleached — ^Testing the Bleachinfl 
Liquor — Bleaching Kier — Charging the Kier with Bleaching Liquor — Bleaching Woollen and 
Half-Wool Goods — Preparing the Bleaching Licjuor — Drying the Goods — Magnesium Sulphate 
in Bleaching Liquor — Bleaching Silk — Bleaching i.inen, Cotton, Jute and Ramie Goods — 
Production of Peroxides — Bleaching Feathers— Sodium Peroxide m Washing Powder — 
Barium Peroxide— Bleaching Silk with Barium Peroxide. Perborates.— Salts of Perboric 
Acid — Properties of Perborates — ^Ammonium Perborates — Sodium Perborates — Perborax — 
Merck's Sodium Perborate— Sapo»zon— Testing Sodium Perborate. Ozone. — Formation of 
Ozone — Ozone Generators— Chemical Production of Ozone— Properties of Ozone — Employ- 
ment of Ozone in Bleaching. Sodium Bisulphite and Hydrosulphurous Acid.— Bleaching 
with Sulphur Dioxide — Bleaching Wool with Hydrosulphurous Acid— Sodium Hydrosulphite 
— Properties of Sodium Bisulphite — Bleaching Processes — Bleaching Manila Hemp — After- 
treatment with Bisulphite — Bleaching Straw— Bleaching Leather. Discharging Colour from 
Textile Fabrics with Hydrosulphurous Acid.- Preparing the Discharge— Discharging 
Colour from Shoddy suid Dyed Fabrics— Stable Hydrosulphite — Method of Using Hydrosul- 
phite — Eradite—Cassella's Hyraldite — Discharging with Hyraldite — Increasing the Dis- 
charging Effect — Stable Hydrosulphites. Permanganate. — Bleaching with Permanganate 
— Action of Permanganate — Bleaching Wool or Silk— Addition of Magnesium Sulphate to 
the Bleaching Liquor — Strength of Permanganate Solution — New Process for Bleaching Jute 
—Bleaching Skins— Bleaching Straw— Bleaching Ivory. Hydrogen Peroxide.— Constitution 
and Properties — Preparation — Crystalline Hydrogen Pero«ide— Properties of Hydrogen 
Peroxide Solutions — Stability — Commercial Hydrogen Peroxide Solutions — Decomposition 
of Hydrc^en Peroxide— Purity of Hydrogen Peroxide — Storage Vessels — Care in Handling 
— Instability of Solutions— Reagent for Hydrogen Peroxide— Valuing Hydrc^en Peroxide 
Solutions — ^Testing Hydrogen Peroxide — Bleaching Wool with Hydrc^en Peroxide — Pre- 
liminary Treatment— Bleaching Bath— After Treatment— Bleaching Silk with Hydrogen 
Peroxide — Bluing before Bleaching— Bleaching Cotton with Hydrogen Peroxide — Bleaching 
Linens with Hydrogen Peroxide — Bleaching Jute with Hydrogen Peroxide — Bleaching Various 
Vegetable Fibres with Hydro/^en Peroxide — Bleaching Straw, Wood, etc., with Hydrogen 
Peroxide— Bleaching Leather with Hydrogen Peroxide— Bleaching Ivory, Horn. Bones and 
Similar Articles— Bleaching Hair— Bleaching Sponges with Hydrogen Peroxide. Bleaching 
Pats, Oils, Wax and Paraffin.— New Process for Bleaching Fats and Oils— Bleaching Wax 
—Bleaching Soap— Decrolin and Blankite for Bleaching Soap— Bleaching Glue. Solid, Stable 
Caldum Hypochlorite and Bleaching Soda.— Stable Calcium Hypochlorite— Bleaching 
Soda. Electric Bleaching.— Electrolytic Bleaching Lye— Judging the Utility of Electric 
Bleaching Plant — Bleaching Experiment with Electrolysed Sodium Chloride Solution — 
Electrolytic Decomposition of Sodium Chloride— Observations of Forster and MuUer — Types- 
of Blectrolyser— Electrolvtic Bleach— Schuckert Plant— Schoop's Electrolytic Bleaching 
Apparatus — Kellner Bleaching Apparatus, Construction — Method of Working — Mounting the 
Apparatus— Determining the Bleaching Power of Electrolytic Liquors, Volumetric Method- 
Bleaching with Electrolytic Bleaching Liquor. 

Part 11., Detergents. — Behaviour of Various Fabrics in the Presence of Chemical Re^ 
agents— Methods of Removing Stains— Chemical Cleaning and Detergents. Benzine Soaps. 
— Removing Stsuns with Benzine Soap and its Solutions — ^Antibenzine Pyrine« or RichteroL 
Extractive Detergents and Detergent Mixtures. Carbon Tetrachloride.— Properties. 
Aceto-Oxalic Addas a Detergent ; Special Methods of Removing Stains. Bleaching- 
Processes Used in Chemical Cleaning.— Bleaching with Potassium Permanganate- 
Reducing Effect of Sulphur Dioxide — Reduction with Hydrogen Peroxide— Reduction with- 
Hydrosulphurous Acid — Seyda's Reduction Process — Combined Method of Removing Stains — 
Hyraldite as a Detergent and Bleaching Agent. Hydrogen Peroxide as a Detergent.— 
Behaviour of Hydrogen Peroxide toward Coloured Fabrics. Oxygen as a Detergent. — 



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Contents of ** Modern Bleaching Asents and Determents"— 

continuea. 
Behaviour of Oxyiienol toward Dyed Fabrics. Sodlam Peroxide as a Detergrent.— Sodium 
Peroxide Soap. Sundry New Deterrents and Cleantingr Agents.— Tetrapol—Lavado— 
Novol— Wetss's Benzine Washing Preparation — Hexol— Steinberg's Detergent Oil— Ozenite— 
Ozonal— Quillola— Oruner's Washing Powder- Eureka Washintf Powder— Detergent Soaps 
that Liberate Oxygen— Klein's Detergent Soap— Detergent for Sensitive Colours— Poltzow's 
Detei^ent Soap — WolzendorfPs Cyanide and Photographer's Ink — Detergent Liquids— 
Hummel's Deter|{ent Liquid— Detergent Paste — Blanchissine — Henkel's Persil— Reinol, Triol, 
Tetra-Isol, Benzin-Isol, Terpin-Isol, Isobenzine Soap and Iso Soap. 

Cotton Spinning and Gombinge 

COTTON SPINNING (First Year). By Thomas Thornley, 
Spinning Master, Bolton Technical School. 160 pp. Eighty-four Illus- 
trations. Crown 8vo. Second Impression. Price 3s. net. (Post free, 
3s. 4d. home ; 3s. 6d. abroad.) 

COTTON SPINNING (Intermediate, or Second Year). By 
Thomas Thornley. Second Impression. 180 pp. Seventy Illustra- 
tions. Crown 8vo. Price 5s. net. (Post &ee, Ss. 4d. home ; 5s. 6d. 
abroad.) 

COTTON SPINNING (Honours, or Third Year). By Thomas 
Thornley. 216 pp. Seventy-four Illustrations. Crown 8vo. Second 
Edition. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 

COTTON COMBING MACHINES. By Thos. Thornley, 
Spinning Master, Technical School, Bolton. Demy 8vo. 117 Illustra- 
tions. 300 pp. Price 7s. 6d. net. (Post free, Ss. home ; 8s. 6d. abroad.) 

Flax, Hemp and Jute Spinning. 

MODERN FLAX, HEMP AND JUTE SPINNING AND 
TWISTING. A Practical Handbook for the use of Flax, 
Hemp and Jute Spinners, Thread, Twine and Rope Makers. By 
Herbert R. Carter, Mill Manager, Textile Expert and Engineer, 
Examiner in Flax Spinning to the City and Guilds of London 
Institute. Demy 8vo. 1907. With 92 Illustrations. 200 pp. Price 
7s. 6d. net. (Post free, 7s. 9d. home ; 8s. abroad.) 

PIBRES USED IN TEXTILE AND ALLIED INDUS- 
TRIES. By C. AiNSwoRTH Mitchell, B.A. (Oxon.), F.I.C., 
and R. M. Prideaux, P.I.C. With 66 Illustrations specially drawn 
direct from the Fibres. Demy Svo. 200 pp. Price 7s. 6d. net. 
(Post free, 7s. 9d. home ; 8s. abroad.) l^ust published. 

Contents. 

Classiflcation, General Characteristics, and Microscopical Examination of Fibres — Stegmata 
— Chemical Examination — Ultimate Fibres — Methyl Value — Moisture in Fibres. Wool. — 
Kature of Wool — Commercial Varieties— Characteristics of Good Wool — Merino — Micro- 
scopical Appearance — Mould in Wool — Felting Property— Curl of Wool— Chemical Composi- 
tion — Action of Reagents on Wool — Chlorinised Wool — Detection of Dyed Fibres in Wool — 
Conditioning of Wool. Vicuna— Camel Hair— Alpaca— Llama Haii^Mohalr— Cashmere 
— Qoats* Half— Cow Hair— Horse Hair- Deer Hair— Reindeer Hair— Rabbits* Hair- 
Cats* Hair— DoffS* Hair— Kangaroos' Hair— Human Hair. Silk.— Origin of Silk- 
Reeling— Waste Silk— History— Commercial Varieties of Thread— Size of Yams— Wild Silks 
— Microscopical Characteristics — Colour of Silk — Size of Fibres — Strength and Elasticity — 
Sp^ific Gravity— whemical Composition — Fibroin — Sericin — Hydrolysis of Silk Proteins — 
Action of Chemical Agents — Absorption of Tannin — Weighting — Differentiation and Separation 
from other Fibres. Cotton.— Origin— History— Commercial Varieties— Structure of the 
Fibre — Cell Walls — Dimensions of Fibre — Chemical Composition — Cellulose — Action of 
Reagents — Nitrated Cotton — Examination of Bleached Fabrics — Absorption of Tannin — 
Absorption of Gases — ^Absorption of Dyestuffs — " Animalizing " of Cotton — Sized Cotton — 
Polished Cotton— Mould in Cotton— Waterproofed Cotton. Mercerised Cotton.— History- 
Structural Alteration of Fibres — Affinity for Dyestuffs — Chemical Changes in Mercerisation — 
Effect upon Strength of Fibre — Measurement of Shrinkage — Reactions and Tests for Mercer- 
ised Cotton— Dyestuff Tests, Artificial Silks.— Historical— Outline of Processes— Strength 



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aad Elasticity — Covering Power — Specific Gravity — Water — Microscopical Appearance — Re- 
actions and Chemical Tests. Linen and Ramie.— Linen— Source— Varieties of Commercial 
Flax — Retting of Flax— Lustrous Linen — Use of Linen as a Textile— Chamcteristics of the 
Fibre — Structure — ^Action of Reagents — Physical Properties — Composition — Flax Wax. 
Ramie — Source — Preparation — History — Properties — Composition. Jute and otlier 
Fibres. — ^Jute — Source — Commercial Varieties — Properties — Microscopical Appearance — 
Chemical Composition — ^The Cellulose of Jute — Lignocellulosee — Chemical Reactions. Hemp. 
— Source — History — Varieties — Properties — Microscopical Appearance— Chemical Composi- 
tion. Sisal Hemp. — Properties — Microscopical Characteristics — Chemical Composition. 
Pita Fibre. Manila Hemp.— Characteristics— JVIusa Paradisiaca Fibre. Banana Fibre. 
Andansonia Fibre. — Differentiation of Jute : Manila and Andansonia. Sanseviera Fibre 
(Bowstringr Hemp).— Source. Sunn Hemp— Qambo Hemp— New Zealand Flax— 
Manritius HempT-Yercum Fibre— Pine Apple Fibre. Brash Fibres.— Cocoanut Fibre 
(Coir) — Characteristics — Ixtle Fibre — Piassava — Brazilian Piassava — ^Af rican Piassava. 
Vegetable Downs and Upholstery Fibres.— Bombax Cottons— Kapok— Ochroma Down— 
Kumbi or Galgal — Vegetable Silk — Asclepias Cotton — Calotropis Down — Beaumantia Down — 
Other Vegetable Silks— Vegetable Wool— Tillandsia Fibre— Vegetable Horsehair. Index. 

Collieries and MineSa 

RECOVERY WORK AFTER PIT FIRES. By Robert 
Lamprecht, Mining Engineer and Manager. Translated from the 
German. Illustrated by Six large Plates, containing Seventy-six 
Illustrations. 175 pp., demy 8vo. Price 10s. 6d. n6t. (Post free, 
lOs. lOd. home; Us. abroad.) 

VENTILATION IN MINES. By Robert Wabner, Mining 
Engineer. Translated from the German. Royal 8vo. Thirty Plates 
and Twenty-two Illustrations. 240 pp. Price 10s. 6d. net. (Post free, 
lis. home ; lis. 3d. abroad.) 

HAULAGE AND WINDING APPLIANCES USED IN 
MINES. By Carl Volk. Translated from the German. 
Royal 8vo. With Six Plates and 148 Illustrations. 150 pp. Price 
8s. 6d. net. (Post free, 9s. home ; 98. 3d. abroad.) 
Contents. 

Haulage Tubs and Tracka— Cages and Winding Applisuices— 
I Shafts — Winding without Ropes — Haulage in Levels and< 
irground Engines — Machinery for Downhill Haulage. 

THE ELECTRICAL EQUIPMENT OF COLLIERIES. By 

W. Galloway Duncan, Electrical and Mechanical Engineer, Member 
of the Institution of Mining Engineers, Head of the Government School 
of Engineering, Dacca, India ; and David Penman, Certificated Colliery 
Manager, Lecturer in Mining to Fife County Committee. Demy 8vo. 
310 pp. 155 Illustrations and Diagrams. Price 10s. 6d. net. (Post 
free, lis. home ; lis. Sd. abroad.) 

Contents. 
Qeneral Principles, Magnetism, Units, Cells, etc.— Dynamos and Motors— Trans- 
mission and Distribution of Power— Prime Movers— Lightinff by Blectricity— Initial' 
Outlay and Working Cost of Electrical Installations— Electricity Applied to Coal- 



Haulage Appliances — Ropes 
Winding Engines for Vertical _ 

Inclines — The Working of Underground Bngines-^Machinery for Downhill l^aulage. 



cuttinor— Electric Haulage, Winding, and Locomotives— Electric Pumps and Pump- 
ing- Electric- Power Drills and Und" . ^ . - --..-... 
BTec 

parison of the Different Modes of Transmitting Powei^-Dangers 

Use of Electricity in Colleries— Appendix : Questions suitable lor students preparing for 



ilectric- Power Drills and Underground Coal Conveyers— Typical Colliery 
-ical Installations— Miscellaneous Applications of the Electric Current— Com- 
parison of the Different Modes of Transmitting Powei^Dangers Occurring from the 



colliery managers' examinations — Index. 

Dental Metallurgy. 

DENTAL METALLURGY : MANUAL FOR STUDENTS 
AND DENTISTS. By A. B. Griffiths, Ph.D. Demy 
8vo. Thirty-six Illustrations. 200 pp. Price 78. 6d. net. (Post free, 
78. lOd. home ; Ss. abroad.) 

Contents . 

Introduction— Physical Properties of the Metals— Action of Certain Agents on Metals — 
Alloys— Action of Oral Bacteria on Alloys— Theory and Varieties of Blowpipes — Fluxes — 
Furnaces and Appliances — Heat and Temperature — Gold — Mercury — Silver — ^Iron— Copper- 
Zinc — Magnesium— Cadmium — Tin — Lead — Aluminium — Antimony — Bismuth — Palladium — 
Platinum— Iridium— Nickel— Practical Work— Weights and Measures. 



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26 

Engineering, Smoke Prevention 
and Metallurgy. 

THE PREVENTION OF SMOKE. Combined with the 

Economical Combustion of Fuel. By W. C. Popplbwell, M.Sc, 

A.M.Inst., C.B., Consulting Engineer. Forty-six Illustrations. 190 pp. 

Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. Sd. abroad.) 

Contents. 

Fuel and Combustion— Hand Firing in Boiler Furnaces— Stoking by Mechanical Means — 
Powdered Fuel — Gaseous Fuel— Efficiency and Smoke Tests of Boilers— Some Standard 
Smoke Trials— The Legal Aspect of the Smoke Question— The Best Means to be adopted for 
ithe Prevention of Smoke— Index. 

OAS AND COAL DUST FIRING. A Critical Review of 
the Various Appliances Patented in Germany for this purpose since 
1885. By Albert Putsch. 130 pp. Demy 8vo. Translated from the 
German. With 103 Illustrations. Price 5s. net. (Post free, 5s. 4d. 
home ; 5s. 6d. abroad. ) 

Contents. 

Generators — Generators Employing Steam — Stirring and Feed Regulating Appliances^ 
Direct Generators — Burners — Regenerators and Recuperators — Glass Smelting Furnaces^ 
Metallurgical Furnaces — Pottery Furnace — Coal Dust Firing — Index. 

THE HARDENING AND TEMPERING OF STEEL 
IN THEORY AND PRACTICE. By Fridolin Reiser. 
Translated from the German of the Third Edition. Crown 8vo. 
120 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.) 
Contents, 
steel— Chemical and Physical Properties of Steel, and their Casual Connection- 
Classification of Steel according: to Use— Testing: the Quality of Steel — Steel- 
Hardenine— Investigation of the Causes of Failure in Hardening:— Res:eneration of 
Steel Spoilt in the Furnace— Welding: Steel— Index. 

SIDEROLOGY: THE SCIENCE OF IRON (The Con- 
stitution of Iron Alloys and Slags). Translated from German of 
Hanns Preiherr v. Juptner. 350 pp. Demy 8vo. Eleven Plates 
and Ten Illustrations. Price 10s. 6d. net. (Post free, lis. home; 
lis. 6d. abroad.) 

Contents. 
The Theory of Solution. — Solutions — Molten Alloys — ^Varieties of Solutions — Osmotic 
^Pressure — Relation between Osmotic Pressure and other Properties of Solutions — Osmotic 
Pressure and Molecular Weight of the Dissolved Substance — Solutions of Gases— Solid Solu- 
tions — Solubility — Diffusion — Electrical Conductivity — Constitution of Electrolytes and Metals 
—Thermal Expansion. Micrography.- Microstructure— The Micrographic Constituents of 
Iron — Relation between Micrc^raphical Composition, Carbon-Content, and Thermal Treat- 
ment of Iron Alloys— The Microstructure of Slags. Chemical Composition of the Alloys 
of Iron. — Constituents of Iron Alloys — Carbon — Constituents of the Iron Alloys, Carbon — 
opinions and Researches on Combined Carbon — Opinions and Researches on Combined 
Carbon — ^Applying the Curves of Solution deduced from the Curves of Recalescence to the De- 
termination of the Chemical Composition of the Carbon present in Iron Alloys — ^The Constitu- 
ents of Iron — Iron— The Constituents of Iron Alloys — Manganese — Remaining Constituents of 
Iron Alloys— A Silicon— Gases. The Chemical Composition of Slag:.— Silicate Sla^s— 
Calculating the Composition of Silicate Slags — Phosphate Slags— Oxide Slags — ^Appendix — 
Index. 

EVAPORATING, CONDENSING AND COOLING AP- 
PARATUS. Explanations, Formulae and Tables for Use 
in Practice. By E. Hausbrand, Engineer. Translated by A. C. 
Wright, M.A. (Oxon.), B.Sc. (Lond.). With Twenty-one Illustra- 
tions and Seventy-six Tables. 400 pp. Demy 8vo. Price 10s. 6d. net. 
(Post free, lis. home; lis. 6d. abroad.) 
Contents. 

/^^Coefficient of Transmission of Heat, k/, and the Mean Temperature Difference, 01m — 
Parallel and Opposite Currents — ^Apparatus for Heating with Direct Fire — ^The Injection of 
Saturated Steam — Superheated Steam — Evaporation by Means of Hot Liquids — ^The Trans- 
ference of Heat in General, and Transference by means of Saturated Steam in Particulsuc 
—The Transference of Heat from Saturated Steam in Pipes (Coils) and Double Bottoms 
— Evaporation in a Vacuum— The Multiple-effect Evaporator— Multiple-effect Evaporators 



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27 

from which Extra Steam is Taken — The Weight of Water which must be Evaporated from 
100 Kilos, of Liquor in order its Original Percentage of Dry Materials from 1-25 per cent 
up to 20-70 per cent. — The Relative Proportion of the Heating Surfaces in the Blementfr 
of the Multiple Evaporator and their Actual Dimensions — The Pressure Exerted by Currents 
of Steam and Gas upon Floating Drops of Water — The Motion of Floating Drops of Water 
upon which Press Currents of Steam — The Splashing of Evaporating Liquids— The Diameter 
of Pipes for Steam, Alcohol, Vapour smd Air — The Diameter of Water Pipes — The Loss 
of Heat from Apparatus and Pipes to the Surrounding Air, and Means for Preventing, 
the Loss— Condensers— Heating Liquids by Means of Steam— The Cooling of Liquids— 
The Volumes to be Exhausted from Condensers by the Air-pumps — A Few Remarks on Air- 
pumps and the Vacua they Produce— The Volumetric Efficiency of Air-pumps— The Volumes 
of Air which must be Exhausted from a Vessel in order to Reduce its Original Pressure to a 
Certain Lower Pressure — Index. 

Sanitary Plumbing, Electric 
Wiring, Metal Work, etc. 

EXTERNAL PLUMBING WORK. A Treatise on Lead 
Work for Roofs. By John W. Hart, R.P.C. 180 Illustrations. 272 
pp. Demy 8vo. Second Edition Revised. Price 7s. 6d. net. (Post 
free, 7s. lOd. home ; 8s. abroad.) 

HINTS TO PLUMBERS ON JOINT WIPING, PIPE 
BENDING AND LEAD BURNING. Third Edition, 
Revised and Corrected. By John W. Hart, R.P.C. 184 Illustrations. 
813 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 8s. home ; 8s. 6d. 
abroad.) 

Contents. 

Pipe Bending — Pipe Bending (continued) — Pipe Bending (continued) — Square Pipe 
Bendings — Half-circular Elbows — Curved Bends on Square Pipe — Bossed Bends — Curved 
Plinth Bends — Rain-water Shoes on Square Pipe — Curved and Angle Bends — Square Pipe 
Fixings— Joint-wiping — Substitutes for Wiped Joints — Preparing Wiped Joints — Joint Fixings 
— Plumbing Irons— Joint Fixings — Use of "Touch" in Soldering — Underhand Joints— Blown 
smd Copper Bit Joints — Branch Joints— Branch Joints (continued)- Block Joints — Block 
Joints (continued) — Block Fixings — Astragal Joints — Pipe Fixings — Large Branch Joints — 
Large Underhand Joints — Solders — Autogenous Soldering or Lead Burning — Index. 

SANITARY PLUMBING AND DRAINAGE. By John 
W. Hart. Demy 8vo. With 208 Illustrations. 250 pp. 1904. Price 
7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.) 

ELECTRIC WIRING AND FITTING FOR PLX7MBERS 
AND GASFITTERS. By Sydney F.Walker, R.N., M.I.E.E., 
M.I.Min.E., A.M.Inst.C.E., etc., etc. Crown 8vo. 150 pp. With Illus- 
trations and Tables. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. 
abroad.) 

Contents. 

Chapter I., Biectrlcal Terms Used.— Pressure and Current— The Volt— Ampere- 
Electrical Resistance— Earth— Continuous and Alternating Currents— The Electric Circuit— 
Leakaj^e— Heating of Conductors— Size and Forms of Conductors— The Kilowatt— Loss of 
Pressure — Arrangement of Conductors— Looping In — ^The Three Wire System — Switches — 
Puses— Circuit— Breakers. IL, The Insulatloii of Wires, Their Protection, Plxlnff, etc. 
—Conductors Insulated with Paper and Similar Materials— Sparking between Conductors 



Pressure — Arrangement of Conductors— Looping In — ^The Three Wire System — Switches — 
- ' ^ ' - -» - -ation of Wires, Their r • ~ • 

Similar Materials — Sparl 
— Dialite Insulation— Flexible Cords — Concentric Conductors— Twin Conductors— Three-Core 
Cables— Fireproof Insulation for Conductors— Jointing— T Joints— Covering T Joints in Vut 
canized Rubber Cables. III., Plxtnir the Wlrinif and Cables.— Laying Out the Route— The 
Protection of the Wires and Cables— Wood Casing— Metallic Conduits— Non-Metallic Con 
ductors— Fixing the Conduits and Running Wires in Them— Drawing Wires into Tubes— To 
Avoid Shock. IV., Lamps.- The Incandescent Lamp— Lamp Holders— Lamp Fittings— The 
Nemst Lamp. V., Switches, Pases, Distribution Boards, etc.— The Electricity Meter- 
Prepayment Meters. 

THE PRINCIPLES AND PRACTICE OF DIPPING, 
BURNISHING, LACQUERING AND BRONZING 
BRASS WARE. By W. Norman Brown. 35 pp. Crown 
8vo. Price 28. net. (Post free, 28. 3d. home and abroad.) 

THE HISTORY OF INCANDESCENT LAMPS. By G. 

Basil Barham, A.M.I.B.B. Illustrated. ''In preparation^ 



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28 

A HANDBOOK ON JAPANNING AND ENAMELLING 
FOR CYCLES, BEDSTEADS, TINWARE, ETC. By 

William Norman Brown. 52 pp. and Illustrations. Crown 8vo. 
Price 2s. net. (Post free, 2s. Sd. home and abroad.) 

THE PRINCIPLES OF HOT WATER SUPPLY. By 

John W. Hart, R.P.C. With 129 Illustrations. 177 pp., demy 8vo. 
Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. abroad.) 

House Decorating and Painting. 

THREE HUNDRED SHADES AND HOW TO MIX 
THEM. For Architects, Painters and Decorators. By A. 
Desaint, Artistic Interior Decorator of Paris. The book contains 100 
folio Plates, measuring 12 in. by 7 in., each Plate containing specimens 
of three artistic shades. These shades are all numbered, and their 
composition and particulars for mixing are fully given at the beginning 
of the book. Each Plate is interleaved with grease-proof paper, and 
the volume is very artistically bound in art and linen with the Shield 
of the Painters' Guild impressed on the cover in gold and silver. Price 
21s. net. (Post free, 21s. 6d. home ; 22s. 6d. abroad.) 

HOUSE DECORATING AND PAINTING. By W. 

Norman Brown. Eighty-eight Illustrations. 150 pp. Crown 8vo. 
Price 3s. 6d. net. (Post free, 3s. 9d. home and abroad.) 

A HISTORY OP DECORATIVE ART. By W. Norman 
Brown. Thirty-nine Illustrations. 96 pp. Crown 8vo. Price Is. net. 
(Post free, Is. 3d. home and abroad.) 

17VORKSHOP WRINKLES for Decorators, Painters, Paper- 
hangers and Others. By W. N. Brown. Crown 8vo. 128 pp. Second 
Edition. Price 2s. 6d. net. (Post free, 2s. 9d. home ; 2s. lOd. abroad.) 

Brewing and Botanical. 

HOPS IN THEIR BOTANICAL, AGRICULTURAL 
AND TECHNICAL ASPECT, AND AS AN ARTICLE 
OF COMMERCE. By Emmanuel Gross, Professor at 
the Higher Agricultural College, Tetschen-Liebwerd. Translated 
from the German. Seventy-eight Illustrations. 340 pp. Demy Svo. 
Price 10s. 6d. net. (Post free, lis. home; lis. 6d. abroad.) 
Contents. 

HISTORY OF THE HOP— THE HOP PLANT— Introductory— The Roots— The Stem— 
-and Leaves — Inflorescence and Flower: Inflorescence and Flower of the Male Hop; In- 
florescence and Flower of the Female Hop — ^The Fruit and its Glandular Structure: The 
Fruit and Seed — Propagation and Selection of the Hop — Varieties of the Hop : (a) Red Hops; 



ib) Green Hops; (c) Pale Green Hops — Classification according to the Period of Ripening: 
Early August Hops ; Medium Early Hops ; Late Hops — Injuries to Growth — Leaves Turning 
Yellow, Summer or Sunbrand, Cones Dropping Off, Honey Dew, Damage from Wind, Hsu! 



jind Rain ; Vegetable Enemies of the Hop : Animal Enemies of the Hop — Beneficial Insects on 
Hops— CULTIVATION— The Requirements of the Hop in Respect of Climate, Soil and 
Situation : Climate ; Soil ; Situation — Selection of Variety and Cuttings — Planting a Hop 
Garden : Drainage ; Preparing the Ground ; Marking-out for Planting ; Planting ; Cultivation 
and Cropping of the Hop Garden in the First Year — Work to be PeHFormed Annually in the 
Hop Garden: Working the Ground; Cutting; The Non-cutting System; The Proper Per^ 
-formance of the Operation of Cutting: Method of Cutting : Close Cutting, Ordinary Cutting, 
The Long Cut, The Topping Cut; Proper Season for Cutting: Autumn Cutting, Spring 
Cutting; Manuring; Training the Hop Plant: Poled Gardenat, Frame Training; Principal 
Types of Frames Pruning, Cropping, Topping, and Leaf Stripping the Hop Plant ; Pickinfi, 
Drying and Bagging— Principal and Subsidiary Utilisation of Hops and Hop Gardens— Life 
x>f a Hop Garden ; Subsequent Cropping— Cost of Production, Yield and Selling Prices. 

Preservation and Storage— Physical and Chemical Structure of the Hop Cone— Judging 
■the Value of Hops. 
Statistics of Production— The Ho|r Trade— Index. 



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29 

Wood Products, Timber and 
Wood Waste. 

WOOD PRODUCTS : DISTILLATES AND EXTRACTS. 

By P. DuMESNY, Chemical Engineer, Expert before the Lyons Com- 
mercial Tribunal, Member of the International Association of Leather 
Chemists; and J. Noybr. Translated from the French by Donald 
Grant. Royal 8vo. 320 pp. 103 Illustrations and Numerous Tables. 
Price 10s. 6a. net. (Post free, lis. home ; lis. 6d. abroad.) 
Contents. 
Part I., Wood Distillation— Principal Products from tlie Carbonisation of Wood- 
Acetates— Secondary Products of the Distillation of Wood— Acetone— Analysis of 
Kaw Materials and Finished Products— Appendix— The Destructive Distillation of Olive 
Oil Residuals. Part II., Manufacture and Testing of Tan Wood Bxtracts and their 
Utilisation in Modem Tanneries— Plant and BquTpment for Treating Chestnut Wood 
—Analysis of Tanning Substances— The Official Method of the International Association 
of Leather Chemists, with Supplementary Notes. 

TIMBER : A Comprehensive Study of Wood in all its Aspects 
(Commercial and Botanical), showing the Different Applications and 
Uses of Timber in Various Trades, etc. Translated f^om the French 
of Paul Charpbntier. Royal 8vo. 437 pp. 178 Illustrations. Price 
12s. 6d. net. (Post free, ISs. home ; 14s. abroad.) 
Contents. 
Physical and Chemical Properties of Timbei^-Composition of the Vegetable Bodies 
— Chim Elements — M. Premy's Researches — Elemental^ Oi^ans of Plants and especially of 
Forests — EHfferent Parts of Wood Anatomically and Chemically Considered — General Pro- 
perties of Wood— Description of the Different Kinds of Wood— Principal Essences with 
Caducous Leavefr— Coniferous Resinous Trees— IMvision of the Useful Varieties of Timber 
in the Different Countries of the Qlol>e— European Timber— African Timber— Asiatic 
Timber— American Timber— Timber of Oceania— Forests — General Notes as to Forests ; their 
Influence— Opinions as to Sylviculture— Improvement of Forests— Unwooding and Rewooding 
—Preservation of Forests— Exploitation of Forests— Damage caused to Forests— Different 
Alterations— The Preservation of Timbei^-Generalities— Causes and Progress of De- 
terioration — History of Different Proposed Processes— Dessication— Superficial Carbonisation 
of Timber— Processes by Immersion — Generalities as to Antiseptics Employed— Ingection 
Processes in Closed Vessels— The Boucherie System, Based upon the Displacement of the 
Sap — Processes for Making Timber Uninflammable — Applications of Timber— Generalities 
—Working Timber— Paving— Timber for Mines— Railway Traverses— Accessorv Products- 
Gums— Works of M. Fremy— Resins— Barks— Tan— Application of Cork— The Application of 
Wood to Art and Dveing— Different Applications of Wood— Hard Wood— Distillation of 
Wood— Pyroligneous Acid— Oil of Wood— Distillation of Resins— Index. 

THE UTILISATION OF WOOD WASTE. Translated from 
the German of Ernst Hubbard. Crown 8vo. 192 pp. Fifty Illustra- 
tions. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 

Building and Architecture. 

THE PREVENTION OF DAMPNESS IN BUILDINOS; 

with Remarks on the Causes, Nature and E£Fect8 of Saline, Efflores- 
cences and Dry-rot, for Architects, Builders, Overseers, Plasterers, 
Painters and House Owners. By Adolf Wilhblm Keim. Translated 
from the German of the second revised Edition by M. J. Salter, F.I.C, 
P.C.S. Bight Coloured Plates and Thirteen Illustrations. Crown 8vo. 
115 pp. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 4d. abroad.) 

HANDBOOK OF TECHNICAL TERMS USED IN ARCHI- 
TECTURE AND BTHLDING, AND THEIR ALLIED 
TRADES AND SUBJECTS. By Augustine C. Passmore. 
Demy 8vo. 380 pp. Price 78. 6d. net. (Post free, Ss. home ; 8«, 6d. 
abrofluL) 



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30 

The Preserving of Foods and 
Sweetmeats. 

THE MANUFACTURE OF PRESERVED FOODS AND 
SWEETMEATS. By A. Hausner. With Twenty-eight 
Illustrations. Translated from the German of the third enlarged 
Edition. Crown 8vo. 225 pp. Price 78. 6d. net. (Post free, 7s. 9d. 
home; 7s. lOd. abroad.) 

Contents. 
The Manufacture of Conserves— Introduction— The Causes of the Putrefaction of Pood 
— ^The Chemical Composition of Poods — The Products of Decomposition — The Causes of Per- 
mentation and Putrefaction — Preservative Bodies— The Various Methods of Preserving Pood 
— The Preservation of Animal Pood — Preserving Meat by Means of Ice — The Preservation 
of Meat by Charcoal — Preservation of Meat by Drying — The Preservation of Meat by the- 
Exclusion of Air — The Appert Method — Preserving Flesh bjr Smoking — ^Quick Smoking — Pre- - 
serving Meat with Salt — Quick Salting by Air Pressure — Quick Salting by Liquid Pressure — 
Gamgee's Method of Preserving Meat — The Preservation of Eggs — Preservation of White 
and Yolk of Egg — Milk Preservation — Condensed Milk — The Preservation of Pat — Manu- 
facture of Soup Tablets— Meat Biscuits— Extract of Beef— The Preservation of Vegetable 
Foods in General — Compressing Vegetables — Preservation of Vegetables by Appert's Method 
—The Preservation of Fruit — Preservation of Fruit by Storage — The Preservation of Fruit 
by Drying— Drying Fruit by Artificial Heat — Roasting Fruit — The Preservation of Fruit with 
Sugar — Boiled Preserved Fruit — The Preservation of Fruit in Spirit, Acetic Acid or Glycerine 
—Preservation of Fruit without Boiling — Jam Manufacture — The Manufacture of Fruit 
Jellies— The Making of Gelatine Jellies— The Manufacture of " Sulzen "—The Preservation of 
Fermented Beverages— The Manufacture of Candies— Introduction— The Manufacture <rf 
Candied -Fruit — The Manufacture of Boiled Sugar and Caramel — The Candying of Fruit — 
Caramelised Fruit — The Manufacture of Sugar Sticks, or Barley Sugar — Bonbon Making- 
Fruit Drops — The Manufacture of Drag^es — The Machinerv and Appliances used in Candy 
Manufacture — Dyeing Candies and Bonbons — Essential Oils used m Candy Making — Fruit 
Essences — The Manufacture of Filled Bonbons, Liqueur Bonbons and Stamped Lozenges — 
Recipes for Jams and Jellies — Recipes for Bonbon Making — Drag^es — Appendix— Index. 

RECIPES FOR THE PRESERVING OF FRUIT, VEGE- 
TABLES AND MEAT. By E. Wagner. Translated 
from the German. Crown 8vo. 125 pp. With 14 Illustrations. Price 
5s. net. (Post free, 5s. 3d. home ; 5s. 4d. abroad.) 
Contents* 

Part 1. Preserved Fruits.— Green Almonds— Goosebernes-Strawberries— Currants- 
Cherries — Black Nuts — White Nuts— Apricots — Greenj 



Melons— Apples — Chestnuts— Angelica— Pineapple. Canned Fruit. — Gooseberries— Cherries 
—Apricots— Plums— Rhubarb. Glazed and Candied Fruits.— Glazing Fruit- Candied 
Fruit — Blue Plums— Glazed Chestnuts — Glazed Pineapple Slices— Crystallised Strawberries. 
Marmalades, Jams and Fruit Juices. — Strawberry Marmalade— Cherry Marmalade — 
Jams — Fruit Jellies— Raspberry Juice — Cherry Juice— Lemon Syrup — Pineapple Juice. Prult 



Pulp for ices. Citron Peel and Oran&re Feel. Part II. Preserved Veffetabies.- 

Asparagus — Peas — Beans — Carrots — Spinach — Artichokes — Tomatoes — Mixed Vegetables- 
Tinned Julienne — Celery — Mushrooms — ^Tru£Eles— Pickled Gherkins— Gherkins in Mustard — 



Mixed Pickles. Part III. Preserved Meats.— Veal Cutlets— Pricondeau of Veal— Calves 
Head— Bouillon Meat— Ox Tongue— Beef a la Mode— Roast Hare— Roast Venison— Mutton 
and Cabbage — Savoury Paste — Beef Paste — Foie Gras Paste. 

FOODS AND DRUGS. Volume I., Chemistry and Analysis 
of Poods and Drugs. Volume II., Law Relating to Foods and Drugs. 
By E. J. Parry, B.Sc. (Lond.). [In preparation. 

Dyeing Fancy Goods* 

THE ART OF DYEING AND STAINING MARBLE, 
ARTIFICIAL STONE, BONE, HORN, IVORY AND 
WOOD, AND OF IMITATING ALL SORTS OF 
WOOD. A Practical Handbook for the Use of Joiners, 
Turners, Manufacturers of Fancy Goods, Stick and Umbrella Makers, 
Comb Makers, etc. Translated from the German of D. H. Soxhlbt, 
Technical Chemist. Crown 8vo. 168 pp. Price 5s net. Post free, 
58. 3d. home ; Ss. 4d. abroad.) 



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31 



CeUuloid. 



<3ELLULOID : Its Raw Material, Manufacture, Properties and 
Uses. A Handbook for Manufacturers of Celluloid and CeUuloid 
Articles, and all Industries using Celluloid ; also for Dentists and 
Teeth Specialists. By Dr. Fr. Bockmann, Technical Chemist. Trans- 
lated from the Third Revised German Edition. Crown 8vo. 120 pp. 
With 49 Illustrations. Price 5s. net. (Post free, Ss. 3d. home ; 5s. 4d. 
abroad.) 

Contents- 
Chapters I., Raw Materials for the Manufacture of Celluloid : Cellulose and Pyroxylin 
— Gun-cotton — Properties of Gun-cotton — Special Gun cottons for Celluloid Manufacture — 
Nitrating Centrifugalisers— Collodion Wool — Methods of Preparing Collodion Wool— Cam- 
phor — Japanese (Formosa) Camphor, Ordina^ Camphor — Borneo Camphor (Bomeol), 
Sumatra Camphor, Camphol, Baros Camphor)— Properties of Camphor — Artificial Camphor 
—Camphor Substitutes. Il„ The Manufacture of Celluloid ; Manufacturing Camphor by 
the Aid of Heat and Pressure — Manufacture of Celluloid by Dissolving Gun-cotton in an 
Alcoholic Solution of Camphor — Preparing Celluloid by the Cold Process — Preparation with 
an Ethereal Solution of Camphor — Preparation with a Solution of Camphor and Wood 
Spirit. III.. The Employment of Pyroxylin for Artificial SUk : Denitrating 
and Colouring Pyroxylin — Uninflammable Celluloid — Celluloid and Cork Composition — 
Incombustible Celluloid Substitute — Xylonite or Pibrolithoid. IV., Properties of 
CeUuloid; v., Testlnff Celluloid. VI.. Application and Treatment of Celluloid: 
Caoutchouc Industry — Making Celluloid Ornaments — Working by the Cold Process — 
Working by the Warm Process— Celluloid Combs— Celluloid as a Basis for Artificial 
Teeth — Stained Celluloid Sheets as a Substitute for Glass — Celluloid Printing Blocks 
and Stamps— Collapsible Seamless Vessels of Celluloid — Making Celluloid Balls-^Celluloid 
Posters — Pressing Hollow Celluloid Articles— Casting Celluloid Articles — Method for Pro- 
ducing Designs on Plates or Sheets of Celluloid, Xylonite, etc.— Imitation Tortoiseshell — 
Metallic Incrustations — Imitation Florentine Mosaic — Celluloid Collars and Cuffs— Phono- 

fraph Cylinder Composition — Making Umbrella and Stick Handles of Celluloid — Celluloid 
^olls— Celluloid for Ships' Bottoms — Celluloid Pens— Colouring Finished Celluloid Articles — 
Printing on Celluloid— Employment of Celluloid (and Pyroxylin) in Lacquer Varnishes- Index 

Lithography, Printing and 
Engraving. 

PRACTICAL LITHOGRAPHY. By Alfred Seymour. 
Demy 8vo. With Frontispiece and 33 Illus. 120 pp. Price Ss. 
net. (Post free, 5s. 4cl. home; 5s. 6d. abroad.) 
Contents. 

Stones— Transfer Inks— Transfer Papers— Transfer Printing- Litho Press— Press Work- 
Machine Printing— Colour Printing— Substitutes for Lithographic Stones— Tin Plate Printing 
and Decoration — Photo-Lithography. 

PRINTERS' AND STATIONERS' READY RECKONER 
AND COMPENDIUM. Compiled by Victor Graham. 
Crown 8vo. 112 pp. 1904. Price 3s. 6d. net. (Post free, 3s. 9d. home ; 
3s. lOd. abroad.) 

Contents. 

Price of Paper per Sheet, Quire, Ream and Lb.— Cost of 100 to 1000 Sheets at various 
Sizes and Prices per Ream— Cost of Cards— Quantity Table— Sizes and Weights of Paper, 
Cards, etc.— Notes on Account Books— Discount Tables— Sizes of spaces — Leads to a lb.— 
Dictionsu*y — Measure for Bookwork — Correcting Proofs, etc. 

ENGRAVING FOR ILLUSTRATION. HISTORICAL 
AND PRACTICAL NOTES. By J. Kirkbride. 72 pp. 
Two Plates and 6 Illustrations. Crown 8vo. Price 2s. 6d. net. (Post 
free, 2s: 9d. home; 2s. lOd. abroad.) 

TINPLATE PRINTING. By Alfred Seymour. Crown 8vo. 

[In preparation. 

Bookbinding. 

PRACTICAL BOOKBINDING. By Paul Adam. Translated 
from the German. Crown 8vo. 180 pp. 127 Illustrations. Price Se. 
net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.) 



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32 



Sugar Refining. 



THE TECHNOLOGY OF SUGAR : Practical Treatise on 
the Modern Methods of Manufiacture of Sugar from the Sugar Cane and 
Sugar Beet. By John Geddes McIntosh. Second Revised and 
Enlarged Edition. DemySvo. Fully Illustrated. 436 pp. Seventy-six 
Tables. 1906. Price 10s. 6d. net. (Post free, Us. home; lis. 6d. 
abroad.) 

(See " Evaporating^ Condensing^ etc., Apparatus,^* p, 26.) 

Libraries and Bibliography. 

CLASSIFIED GUIDE TO TECHNICAL AND COM< 
MERCIAL BOOKS. Compiled by Edgar Greenwood. 
Demy 8vo. 224 pp. 1904. Being a Subject-list of the Principal 
British and American Books in print ; giving Title, Author. Size, Date, 
Publisher and Price. Price 5s. net. (Post free, Ss. 4d. home ; 5s. 6d. 
abroad.) 

HANDBOOK TO THE TECHNICAL AND ART 
SCHOOLS AND COLLEGES OF THE UNITED 
KINGDOM. Containing particulars of nearly 1,000 Techni- 
cal, Commercial and Art Schools throughout the United Kingdom. 
With full particulars of the courses of instruction, names of principals, 
secretaries, etc. Demy 8vo. 150 pp. Price 3s. 6d. net. (Post free, 
3s. lOd. home ; 4s. abroad.) 

THE LIBRARIES, MUSEUMS AND ART GALLERIES 
YEAR BOOK, 1910-11. Being the Third Edition of Green- 
wood's " British Library Year Book ". Edited by Alex. J. Philip. 
Demy 8vo. 286 pp. Price 5s. net. (Post free, 58. 4d. home ; 5s. 6d. 
abroad.) [jfust published. 

Contents. 

Preface— Introduction— Chronol(^ical List of Adoptions of the Libraries Acts— Public 
Libraries Assessed for the Payment of Rates — Special Collections of Books in Libraries* 
Museums and Art Galleries— Alphabetical Index to Librarians, Curators and Assistants- 
Architects who have Designed Public Libraries — Libraries, Museums and Art Galleries in the 
United Kingdom — Women Librarians Occupying Chief Positions — Women Assistants — 
Methods of Charging or of Issuing Books — Classifications in Use — Public Libraries Opening 
on Sundays — Public Libraries Opening on Bank Holidays — Public Libraries in which Betting 
News is Obliterated— Public Libraries Publishing Magazines, BuUetias, etc. 

THE plumbing] HEATING AND LIGHTING 
ANNUAL FOR 1911. The Trade Reference Book for 
Plumbers, Sanitary, Heating and Lighting Engineers, Builders' Mer- 
chants, Contractors and Architects. Quarto. Bound in cloth and gilt 
lettered. (Published in December, 1910.) Price 3s. net. (Post free, 
3s. 4d. home ; 3s. Sd. abroad.) 

SCOTT, GREENWOOD & SON, 

^ecbnicaf JSooft and ^tade Soutnal publiabets, 

8 Broadway, Ludgate Hill, 
london, e.g. 

Tele^aphio Addrem, ^ Printertei, London ". Telephone, Bank SIOS. 

January, ISH. 



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THIS BOOK IS DUE ON THE LAST BATE 
STAMPED BELOW 

AN INITIAL FINE OF 26 CENTS 

WIl^L BE ASSESSED FOR FAILURE TO RETURN 
THIS BOOK ON THE DATE DUE THE PENALTY 
WILL INCREASE TO SO CENTS ON THE FOURTH 
DAY AND TO SlOO DM THE SEVENTH DAY 
OVERDUE. 



MAR 5 1934 



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